
Class ^ >f 

Book at&S. 






KJ 



W$t l&ural Science Series 

Edited by L. H. Bailey 



THE FEEDING OF ANIMALS 



C&e l&utal Science &me$ 

The Soil. 

The Spraying of Plants. 

Milk and its Products. 

The Fertility of the Land. 

The Principles of Fruit-Growing. 

Bush-Fruits. 

Fertilizers. 

The Principles of Agriculture. 

Irrigation and Drainage. 

The Farmstead. 

Rural Wealth and Welfare. 

The Principles of Vegetable-Gardening. 

Farm Poultry. 

The Feeding of Animals. 



THE 

FEEDING OF ANIMALS 



BY 

WHITMAN HOWARD JORDAN 

Director of the New York Agricultural Experiment Station 



SEGQ&JJl PDITWN. \ ? - i ■ . ■ 



j£eto Sotfe 

THE MACMILLAN COMPANY 

LONDON: MACMILLAN & CO., Ltd. 

1903 

All rights reserved 






je'i 



Copyright, 1901 
By THE MACMILLAN COMPANY 



Set up and electrotyped June, 1901 
Reprinted September, 1903 






lunt U^leassant Wte** 

J. Horace McFarland Company 
Harrisburg • Pennsylvania 






J 



PREFACE 



This volume is the result of an effort to present 
the main facts and principles fundamental to the 
art of feeding animals, as they are now understood. 
It is not a statement of rules or of the details of 
practice, for even if the author regarded himself as 
competent to discuss these he would hold it to be 
unwise to attempt to discriminate in practical matters 
so varied and so complex. 

Neither has an effort been made to harmonize the 
whole mass of experimental data relating to animal 
nutrition. Many of these data are of no value, many 
are very incomplete, and many are apparently con- 
flicting, so that more useful lessons can often be 
drawn from single events in the field of experiment 
and investigation than from the frequently doubtful 
testimony of summaries. 

The author expresses the hope that what he has 
written will not be regarded as having for its ulti- 
mate object the mere exposition of feeding formulas. 
It is to be feared that the German standard rations 
are unfortunately accepted by many as nutrition pre- 

rv) 



vi Preface 

scriptions "to be given according to directions." It 
is time to break away, if we have not already done 
so, from an undiscriminating adherence to mathe- 
matical doses of nutrients, the accuracy of which is 
supposed by some to outweigh all other consider- 
ations and to determine success in feeding. The 
study of animal nutrition may not wisely center 
around feeding standards, as seems to have been the 
tendency of late years. While these formulas are 
certainly an aid in selecting adequate and uniform 
rations, the} 7 are nevertheless merely an imperfect 
expression of relations not fully understood that have 
a greatly variable application in practice, an appli- 
cation judiciously made only through the exercise of 
a judgment enlightened by familiarity with funda- 
mental facts and principles. Rational cattle feeding 
is not to be attained through a blind acceptance of 
existing standard rations but by means of a broad 
understanding of the scientific and practical knowl- 
edge in which these standards had their rise. 

Much of the matter introduced in this connection 
bears no immediate relation to the practical opera- 
tions of feeding. No apology is made for this de- 
parture from the business aspects of the subject. A 
study of the practical relations of science should not 
only promote our material well-being but should also 
lend itself to intellectual stimulus and culture. 



Preface vii 

The chapter on The Feeding of Poultry was writ- 
ten by Mr. William P. Wheeler, who also executed 
the several drawings which appear as illustrations. 
The author is under great obligations to his associ- 
ates, Dr. L. L. Van Slyke and Mr. Frank H. Hall, 
for reading the proof sheets. 

W. H. JORDAN. 

New York State Experiment Station, 
Geneva, N. Y., June 1, 1901. 



CONTENTS 

PART I 

THE PRINCIPLES OF FEEDING 
CHAPTER I 

PAGES 

Introduction: Man's Relation to Animal Life 1-6 

The conditions and problems involved in feeding animals . . 3 

CHAPTER II 
The Relations of Plant and Animal Life 7-10 

CHAPTER III 

The Chemical Elements of Nutrition 11-24 

The elements and their sources: Carbon, Oxygen, Hy- 
drogen, Nitrogen, Sulfur, Phosphorus, Chlorine, 

Potassium, Sodium, Calcium, Iron 12 

Proportions of elements in plants and animals 21 

In plan s 21 

In animals 22 

CHAPTER IV 

The Compounds of Animal Nutrition 25-50 

Classes of matter 26 

(ix) 



Contents 

PAGES 

The classes of compounds 28 

Water 30 

Water in living plants 33 

Water in feeding stuffs 36 

Water in the animal 38 

Ash 41 

The mineral compounds of plants 43 

Variations due to species 43 

The distribution of mineral compounds in the dif- 
ferent parts of the plant 45 

Influence of manufacturing processes on the ash 

constituents 47 

The mineral compounds of animal bodies .... 48 
The distribution of inorganic compounds in the 

animal body , 49 



CHAPTER V 

The Compounds of Animal Nutrition (continued) . . . 51-70 

The nitrogen compounds 51 

Protein 52 

The proteids 55 

The albuminoids 57 

The albumins 58 

The globulins 59 

The modified albuminoids 62 

Coagulating ferments 63 

Heat 64 

Action of acids and alkalies 65 

Ferments of digestion 65 

Combinations 66 

The gelatinoids 68 

Keratin and similar substances 69 

Protein: The non- proteids 69 

Amides 69 

Extractives 70 



Contents xi 

CHAPTER VI 

PAGES 

The Compounds of Animal Nutrition (concluded) . . . 71-92 

The nitrogen -free compounds 71 

Crude fiber 72 

Nitrogen-free extract 74 

The starches 75 

The vegetable gums 78 

The pectin bodies 80 

The sugars , 80 

The acids 83 

Animal carbohydrates 84 

Chemical relations and characteristics of the carbohy- 
drates 85 

Fats or oils 88 

CHAPTER VII 
The Composition of the Bodies of Farm Animals . . . 93-97 

CHAPTER VIII 

The Digestion of Food 98-125 

Ferments 99 

The mouth 104 

The stomach 108 

The intestines 114 

Absorption of the food 119 

Feces 121 

Relation of the different feeding stuff compounds to the 

digestive processes 121 

CHAPTER IX 

Conditions Influencing Digestion 126-141 

Palatableness 126 

Influence of quantity of ration 127 



xii Contents 

PAGES 

Effect of drying fodders 128 

Influence of the conditions and methods of preserving 

fodders 129 

Influence of the stage of growth of the plant 130 

Influence of methods of preparation of food 131 

Influence of grinding 133 

Effect of common salt • 133 

Influence of frequency of feeding and watering animals . 134 

Influence of certain other conditions 134 

Influence of the combination of food nutrients 135 

Conditions pertaining to the animal : species, breed, 

age and individuality 137 

Determination of digestibility 139 



CHAPTER X 

The Distribution and Use of the Digested Food . . 142-150 

The blood 142 

The heart 144 

The lungs 146 

The use of food 147 

Elimination of wastes 148 

The liver 150 

CHAPTER XI 

The Functions op the Nutrients 151-169 

Functions of the mineral compounds of the food .... 152 

Functions of protein 153 

Functions of carbohydrates 155 

Functions of the fats and oils 157 

Food a3 a source of energy 157 

Available energy 163 

Net energy 164 

Energy relations of the several nutrients 166 

Heat relations 167 



Contents xiii 

CHAPTER XII 

PAGES 

Physiological Values of the Nutrients 170-181 

Relative energy and production values of the nutrients, 

singly and as classes 171 

Relative energy values 171 

Relative production values of the different nutrients . 175 
Relative importance of the protein compounds .... 178 

CHAPTER XIII 
Laws of Nutrition 182-185 

CHAPTER XIV 

Sources of Knowledge 186-202 

Conclusions of practice 187 

Practical feeding experiments 188 

Chemical and physiological studies 191 

More accurate methods of investigation 192 

Relation of food to production 194 

The respiration apparatus 196 

Determination of energy values 198 

Calculation of energy value of a ration 198 

Energy value of digested nutrients 199 

Measurement of food combustion 200 

Respiration calorimeter 201 

PART II 

THE PRACTICE OF FEEDING 

CHAPTER XV 

Cattle Foods — Natural Products 203-226 

Forage crops 204 

Green vs. dried fodders 205 

The harvesting of forage crops 207 



XIV 



Contents 



PAGES 

Silage 212 

Nature of changes in silo 213 

Extent of loss in the silo 215 

Ensiling vs. field-curing 217 

Crops for ensilage 218 

Construction of silos 219 

Filling the silo 220 

The straws 223 

l Roots and tubers 224 

Grains and seeds 225 



CHAPTER XVI 

Cattle Foods — Commercial" Feeding Stuffs 227-257 

Classes of commercial by-product feeding stuffs 228 

Wheat offals 228 

Residues from breakfast foods 232 

Brewers' by-products 236 

Residues from starch and glucose manufacture .... 236 

Residues from the manufacture of beet -sugar .... 240 

The oil meals in general 241 

Cottonseed meal 242 

Linseed meal 245 

Chemical distinctions in cattle foods 248 

Coarse foods vs. grains and grain products 249 

Classification according to the proportions of nutrients . 249 

Foods of animal origin 252 

Milk 252 

Dairy by-products » . . 254 

Slaughter-house and other animal refuses 256 



CHAPTER XVII 

The Production of Cattle Foods 258-267 

Soiling crops 263 



Contents xv 

CHAPTER XVIII 

PAGES 

The Valuation of Feeding Stuffs 268-279 

Commercial values 269 

Physiological values 272 

Selection of feeding stuffs 273 

Other standards of valuation 277 

CHAPTER XIX 
The Selection and Compounding of Rations 280-294 

CHAPTER XX 

Maintenance Rations 295-303 

Maintenance food for bovines 297 

Maintenance food for horses 300 

CHAPTER XXI 

Milk Production 304-323 

Milk secretion 306 

Sources of milk solids 307 

The rate of formation of milk solids 308 

The amount and character of the ration for milk production 309 

The sources of protein for milk production 313 

The relation of food to the composition and quality of milk 316 

Effect of food upon the composition of milk 316 

Effect of food upon the flavors of milk and its products . 321 

CHAPTER XXII 

Feeding Growing Animals 324-338 

The feeding of calves 328 

The feeding of lambs 331 

Feeding colts . . . 333 

Feeding the dam ' . 334 

Feeding the colt 335 



xvi Contents 

CHAPTER XXIII 

PAGES 

Feeding Animals for the Production of Meat .... 339-366 

The nature and extent of the growth in beef production . 340 

The food needs of the fattening steer . . , 341 

The selection of a fattening ration 347 

Mutton production 349 

The nature and extent of the growth in fattening sheep . 350 

Food needs of fattening sheep . . 351 

The selection of a ration for sheep 355 

Pork production 357 

Character of the growth in pork production 358 

Food requirements for pork production . 360 

Feeding the dam 360 

Feeding pigs for the market 361 

CHAPTER XXIV 

Feeding Working Animals 367-378 

The horse a machine 367 

The work performed by a horse 368 

The food requirements of a working horse 371 

Source of the ration for working horses 374 

CHAPTER XXV 

The Feeding of Poultry — By William P. Wheeler . . 379-399 

Kinds of foods 379 

Incidental effects of the food 382 

Digestive apparatus 383 

Constituents of the body 387 

Necessity for considering the water 389 

The organic and mineral nutrients in food 389 

The study of rations and deduction of standards .... 392 

Maintenance rations 393 

Rations for laying hens 393 

Rations for young birds 394 



Contents xvii 

CHAPTER XXVI 

PAGES 

The Relation of Food to Production 400-407 



CHAPTER XXVII 

General Management 408-418 

Selection of animals 409 

Selection of cows 409 

The selection of animals for meat production .... 411 

Manipulation of the ration 413 

Quantity of the ration 414 

Environment and treatment of animals 415 



APPENDIX 

Composition and Digestion Tables 419-443 

1. Average composition of American feeding stuffs . . 419-427 

2. Average coefficients of digestion 427-435 

3. Feeding standards 435-438 

4. Fertilizing constituents, American feeding stuffs . 439-443 



INDEX 445-450 



APR 1 1 1904 



THE FEEDING OF ANIMALS 



PART I— THE PRINCIPLES OF FEEDING 

CHAPTER I 

INTRODUCTION: MANS RELATION TO ANIMAL LIFE 

There was a time somewhere in the dim past when 
the beast of the field knew no master. The only obe- 
dience which he rendered to a superior power was an 
unconscious submission to Nature's stern forces. He 
wandered forth at will to find in the untilled pastures 
such food as the wild herbage afforded, and, unre- 
strained, he sought a place of rest in the tangled 
thicket. He knew no refuge from the winter's cold 
and storm but some sheltered nook or forest recess to 
which his brute intelligence guided him, and he was 
his own defense against the dangers which beset him. 

Man had not come to be a controlling factor in the 
development of the various forms of animal life. If 
the brute knew him at all, it was as the huntsman, as 
an enemy, but not as a superior to whom must be paid 
a tribute of service or of food and clothing. The wild 
ox and horse possessed those characteristics which best 
fitted them to cope with the untoward conditions of 
their environment; but there had not yet appeared 

A (1) 



2 The Feeding of Animals 

those specialized capacities of growth, draft, speed or 
production which now render these animals so very 
valuable for the service and sustenance of the human 
family. 

The qualities developed were those demanded by the 
necessities of existence without reference to utility as 
measured by the needs of a higher form of life. The 
fiber of the body must possess endurance, and it mat- 
tered little whether or not the muscle could furnish a 
juicy steak. The brute mother must defend her young 
and supply it with milk, and this being accomplished, her 
maternal functions ceased. She was neither so endowed 
that she could open the fountains of her life to feed 
generously a not too grateful master, nor so submissive 
that she would. The wild horse must be fleet and en- 
during that he might escape the enemy, but not that 
he might bear heavy burdens or win a contest in the 
prescribed form of the race- track. 

In the lapse of centuries there have been many 
changes in the relation of man to the animal creation. 
Bird and beast in various forms have come to minister 
to man's wants, and in their present domesticated con- 
dition are, in their turn, utterly dependent upon him 
for the food and shelter which are necessary to their 
physical welfare, or even existence. It is not too much 
to assert that the domestic animal, in the artificial en- 
vironment imposed upon it, is entirely at man's mercy, 
even in the development of those attributes and char- 
acteristics which otherwise would be determined by the 
demands of an unaided warfare with nature. The juicy 
sirloin of the shorthorn, the almost abnormal milk 



Man Improves the Animal 3 

glands of the champion butter cow, the delicate fiber of 
merino wool, and the marvelous speed of the modern 
race-horse are evidences of man's skill in recasting 
natural types into forms of greater usefulness to him. 
From the animal of nature, under the direction of a 
higher intelligence, has proceeded the animal of civil- 
ization, an organism obedient to the environment which 
has been created for it. 

This interdependence of man and the lower orders 
of life has a vast economic significance. A large part 
of human activity is devoted to the production and 
transportation of food for animals and to the traffic in 
the products of the dairy, slaughter-house and sheep- 
fold, and to their utilization in various ways. The 
prosperity of every farm is maintained to a greater or 
less extent by feeding domestic animals, and our rail- 
roads, our markets, in fact, nearly all our important 
business enterprises, are more or less dependent upon 
the extent and prosperity of animal husbandry. 

THE CONDITIONS AND PROBLEMS INVOLVED IN 
FEEDING ANIMALS 

The first and simplest form of animal husbandry is 
that which was practiced by the nomad. His flocks 
and herds subsisted wholly by grazing and were moved 
from place to place according to the supply of forage 
afforded by different localities. No shelter was pro- 
vided for the animals and no food was stored for their 
use. The only intelligence or special knowledge that 
was brought to bear upon the business of the herdsman 



4 The Feeding of Animals 

was a familiarity with the traditions and superstitions 
touching the care of cattle and the acquaintance which 
a roving life would give with the pastures furnishing 
the most abundant and sweetest wild grasses during the 
various seasons of the year. There was not then even 
a dim promise of the modern traffic in meats or of 
the fine art of dairying as we now know it. As man 
began to give up this wandering life, erect permanent 
dwellings and confine his ownership of land to definite 
limits, he acquired the art of tillage, not only that he 
might have food for his family but also for his cattle. 
He then began to store fodder in stacks, and later in 
barns, to meet the demands of the inclement portions 
of the year. 

For centuries, however, grazing was the chief de- 
pendence for securing the production of meat and milk 
because the foods supplied during the cold season were 
not in such abundance or so nutritious as to sustain 
continuous growth or milk secretion. Even within the 
remembrance of men now living, live stock was not ex- 
pected to produce an increase during the winter months 
but was simply maintained from autumn until spring 
in order that profits might be realized from summer 
pasturage. Formerly the demands of the market were 
much simpler than they are now. Butter and cheese 
were produced almost wholly from summer dairying, 
and no such variety of fresh meats was offered to con- 
sumers during the entire year as is now the case. But 
great changes have occurred during the last fifty years, 
more especially during the past twenty -five. First of 
all, we have a modern type of animal, greatly unlike that 



The Animal of Civilization 5 

of previous times. The ideal dairy cow of to-day is a 
high -pressure milk machine extremely sensitive to her 
environment and demanding a degree of care in manage- 
ment and feeding, if she is to do her safe maximum 
work, which was not necessary with coarser and less deli- 
cate organisms. Every successful dairyman must now 
provide proper winter quarters for his herd and through- 
out the entire year must supply rations that will sup- 
port continuous, generous production. He must do 
this, too, by the use of a greater variety of foods than 
was formerly available. Not only has the number of 
useful forage crops greatty increased, but the average 
farmer no longer produces all the food which his ani- 
mals consume. He now buys numerous kinds of com- 
mercial feeding stuffs. These purchased materials are 
not wholly the cereal grains whose value through long 
experience has come to be measured by certain prac- 
tical standards, but they consist in part of compara- 
tively new by-products from the manufacture of oils, 
starch and human food preparations, — feeding stuffs 
which differ greatly in their nutritive properties. Be- 
sides all these changes, animal husbandry is now called 
upon as never before to feed the prosperous part of 
humanity with high -class products having special qual- 
ities of texture and flavor that depend to some extent 
upon feeding. Certainly the conditions and problems 
to be met in this branch of human industry have grown 
more and more complex. 

We must add to this the fact that, as is true with 
every department of man's activity, science has laid 
her hands upon the business of the farmer and has 



6 The Feeding of Animals 

forced him into a new range of thought and practice. 
This influx of knowledge has greatly influenced the 
requirements for meeting a sharpened competition and 
has rendered it imperative for the practitioner to bring 
to bear upon a great variety of agricultural problems 
a clear understanding of fundamental facts and prin- 
ciples. 

The feeding of animals involves many difficult ques- 
tions. These begin with the production of forage and 
grain crops where it is necessary to discover what ones 
will yield the largest food values per unit of expendi- 
ture. Economy demands that the several feeding stuffs 
which are at command shall be so combined that there 
shall be no waste of material or energy. With several 
considerations in view, a decision must be reached as 
to the most profitable commercial foods to purchase 
when the number is large and the range of prices is 
wide. The influence of the various foods upon the 
quality of the product, especially dairy products, has 
in recent years become an important matter. These 
and related problems confront the stockman and dairy- 
man, and they demand for their wise solution more than 
what is ordinarily designated as practical experience. 
The investigator who shall successfully inquire into 
these matters must possess scientific qualifications of 
a high order; and the practical man, who, in a busi- 
ness way, conforms his methods to the highest stand- 
ard which scientific research has already made possible 
must be familiar with the knowledge fundamental to 
the feeder's art. 



CHAPTER II 

THE RELATIONS OF PLANT AND ANIMAL LIFE 

The foundations of animal life are laid in the plant, 
and with the plant must begin a study of the funda- 
mental facts of animal nutrition. The first step toward 
supplying animals with food is taken when the farmer 
drops seed into the warm earth. As soon as the young 
rootlets from a germinating seed come in contact with 
the soil and the first leaves reach the air, assimilative 
growth begins. 'During the hours of sunlight matter 
is constantly gathered in an invisible way, which, after 
transformation into various compounds, is added to the 
enlarging tissues of the plant. This continues, per- 
haps for a season, until the stalk of grain has reached 
its full height and has attained the ultimate object 
of its existence in the production of seed, or it may 
go on for centuries, so that where now is only the 
acorn there will be the giant oak. The farmer car- 
ries to the field a few pounds of seed and he returns 
to his storehouses laden with tons of new material, 
perhaps hay, perhaps grain. From somewhere, in some 
way, the plant has gathered various substances, often 
no less than ten thousand pounds per acre in a single 
year, and has manufactured them into forms that are 
useful to the husbandman. 

(7) 



8 The Feeding of Animals 

Plant life not only builds tissue: it stores energy, 
as we may easily discover. The farmer's boy learns 
this when he feels the hot glow of the fire that is 
fed by forest wood. The wood disappears, but he is 
warmed by the radiant energy. It has occurred that 
when fuel was scarce and costly and grain was abun- 
dant and cheap, the western farmer has burned his 
corn. All he realized in this case for his labor was 
the warmth which was necessary to make himself and 
family comfortable. As with the wood, the materials 
which were collected from the soil and air have been dis- 
persed in invisible forms during the combustion which 
liberated the heat energy, except a small heap of ashes 
on the hearth. The farmers who raised corn for fuel 
were no richer in storehouse or in pocket. They had 
simply used an available supply of heat, derived from 
the energy which was stored in the plant during its 
growth. 

But ordinarily, grass and grain are produced, not 
for fuel but for food purposes, and in this use of vege- 
table matter we come in contact with a set of phe- 
nomena equally complex and equally important and 
interesting to those of its growth. The calf of to-day 
weighing, perhaps, a hundred pounds, becomes in a few 
years the immense bullock. What is the source Of 
this mass of bone and flesh ? It is merely plant sub- 
stance which in other combinations was collected from 
soil and air. This animal eats his daily ration and 
makes his daily gain of tissue. When his food is with- 
held, his body wastes and he dies. If his food varies 
in amount, his growth is somewhat proportional to the 



Tlit Role of the Plant 9 

quantity eaten. We, therefore, cannot resist the con- 
clusion that the bones, blood and flesh of this ox are 
derived from what he eats. 

The plant does more than to supply building ma- 
terial for the animal body. This living organism is 
kept warm. No matter how cold the surrounding at- 
mosphere, we find by the use of a thermometer that in 
health the ox's temperature remains at about 101° F., 
with but small variation. Just as the western farmer 
obtained heat by burning corn in the fireplace, so does 
the cattle -owner maintain the body temperature of his 
animals at the necessary degree by supplying food to 
be burned. The combustion is not so rapid as occurs 
in the fireplace, still the changes are the same but more 
slowly carried on. 

Food not only builds the ox and warms him, — it 
furnishes him with motive power. The energy which 
the plant acquires during its time of growth is, through 
his vital processes, transformed in part into motion. 
The animal is a living mechanism, a combination of 
muscles and levers which are moved not by means 
of a spontaneous internal generation of energy, but 
through a supply from without, the energy stored in 
the plant. 

If we use the plant for fuel we get heat alone; if 
we feed it to the animals we get heat, motion and the 
production of other forms of matter that have a rela- 
tively high commercial value. In the first instance 
the plant substance, except the mineral portion, is 
wholly broken up into simpler compounds which in 
unseen gaseous forms escape from our possession, the 



10 The Feeding of Animals 

liberated energy becoming manifest as heat. With the 
animal, a greatly varying proportion of the dry matter 
of the plant is retained to form his body substance, 
and the remaining part suffers decomposition, largely 
into the same compounds that are carried away by the 
draft from the fire on the hearth. As a result there is 
built a living organism that is warmed to a tempera- 
ture generally much above that of the surrounding air, 
which is the seat of complex internal activities and is 
capable of performing external work. 



CHAPTER III 

THE CHEMICAL ELEMENTS OF ANIMAL NUTRITION 

The facts which are fundamentally necessary to a 
broad understanding of the economy of cattle feeding, 
pertain, first of all, to the materials out of which vege- 
table and animal tissues are constructed. It is impor- 
tant to know both what these are and what are their 
sources. 

About seventy substances are now believed to be 
chemical elements, i. e., substances that cannot be re- 
solved into two or more simpler ones, and of which, so 
far as known, all forms of matter are composed, the 
variety of combinations being almost infinite. It is 
remarkable that comparatively few of these fundamental 
substances, — about one-fifth, — are intimately related to 
the growth of plants; and those that occupy a promi- 
nent place in animal nutrition are even less in number. 

It is necessary to mention only fifteen elements in 
this connection, some of which are of minor impor- 
tance: carbon, oxygen, hydrogen, nitrogen, sulfur, 
phosphorus, chlorine, silicon, fluorine, potassium, so- 
dium, calcium, magnesium, iron and manganese. 

At ordinary temperatures, four of these, oxygen, 
hydrogen, nitrogen and chlorine, are gases, and the re- 
maining ones are solids. Four are constant and im- 

(11) 



12 The Feeding of Animals 

portant ingredients of the atmosphere; viz., carbon, 
oxygen, hydrogen and nitrogen, and they also exist in 
the soil in gases, as well as in combination in liquids 
and solids; the other eleven, though sometimes present 
in the air in minute quantities, are found to no appre- 
ciable extent except as fixed compounds in water and 
in the crust of the earth, or in plants and animals. 
Nearly all of these elementary substances are absolutely 
essential to the existence of animal life as now con- 
stituted. From the standpoint of necessity, they are, 
therefore, nearly all of equal value, but if we take into 
consideration the relative ease and abundance of the 
supply, certain ones rise to a position of supreme im- 
portance. 

THE ELEMENTS AND THEIR SOURCES 

Carbon. — This is a familiar substance in common 
life. Anthracite coal and charcoal are examples of im- 
pure carbon. Graphite in lead pencils is also carbon, 
and so are diamonds. When wood chars or food is 
burned in an overheated oven the partially decomposed 
materials become black, revealing the presence of car- 
bon, the other elements with which it was associated 
being driven out. The humus of the soil is vegetable 
matter, which, from other causes, has undergone some- 
what the same change. 

An immense quantity of carbon exists in the air, 
combined with oxygen as carbon dioxid or carbonic 
acid gas. The average proportion by weight of this 
compound in the atmosphere is stated to be .06 per 



Carbon 13 

cent, and as the weight of a column of air one inch 
square is fifteen pounds, it follows that over every acre 
of land there is 28.2 tons of carbon dioxid, or 7.7 tons 
of carbon. As we know that plants draw their supply 
of this element from the atmosphere, and as vegetable 
tissue is its only source to the animal, we are able to 
assert, with confidence, that the carbon in the tissues 
of animal life was once floating in space. 

A long time ago, Boussingault determined the aver- 
age yearly amount of carbon which was withdrawn from 
the air by the crops grown on a particular field during 
a period of five years, and found it to be 4,615 pounds. 
This is no more than is acquired by a large crop of 
maize. As a matter of fact, plants, as well as animals, 
contain a larger proportion of this element than of any 
other, and the amount of this substance which enters into 
the processes of growth and decay in the vegetable and 
animal kingdoms is almost beyond comprehension. It 
is natural to wonder whether the atmospheric supply is 
equal to the demand. Any anxieties we may have con- 
cerning this should be removed by learning that during 
many years the percentage of atmospheric carbon has 
not changed appreciably. The processes of decay on 
the earth's surface, the combustion of wood and coal 
as fuel and of carbon compounds by animal life are re- 
turning carbon to the air as rapidly as it is being with- 
drawn. This is the round traveled, — from the air to 
the plant, from the plant to the animal, and from the 
animal back to the air, — a cycle in which this element 
has been moving since life began, and in which it will 
continue to move so long as life exists. 



14 The Feeding of Animals 

Oxygen. — This element is, next to carbon, the most 
abundant component of vegetable and animal tissues, 
and it stands second to none in its relation to the vital 
processes of nearly all forms of life. It is not a sub- 
stance with which we are familiar by sight, because we 
ordinarily come in contact with it as a transparent, 
colorless gas. We live and move in it, for it is an im- 
portant and uniformly abundant constituent of the at- 
mosphere. The air is over one-fifth oxygen by volume, 
the proportion by weight being slightly larger. More 
than twenty -one million pounds of this element are 
contained in the air above a single acre of land, a 
quantity which remains remarkably constant, and which 
is surprisingly uniform over the entire surface of the 
globe. While it is being continuously withdrawn from 
the air for the uses of life and to maintain fuel com- 
bustion and processes of decay, it is, like carbon, as 
continuously returned. 

Vast quantities of oxygen are also contained in 
water, as this compound, which fills the ocean and 
lakes, and is abundant in the crust of the earth, is 
nearly 89 per cent oxygen. It is estimated also that 
the solids in the crust of the earth are one -half oxy- 
gen. That which enters directly into the uses of ani- 
mal life is, however, chiefly that which is derived from 
the atmosphere and water. 

Not a plant grows or animal lives excepting through 
the circulation of oxj^gen, during which it passes into 
fixed combinations and back again to the free form. 
The animal uses the free oxygen in breathing and re- 
turns it to the air in part combined with carbon as car- 



Oxygen — Hydrogen 1 5 

bonic acid, This compound the plant appropriates, re- 
taining the carbon for its tissues and giving back the 
uncombined oxygen to the atmosphere to be again 
used by animals. All decay and many other chemical 
changes require the presence of this element. What 
we speak of as fire is due to its union with the ele- 
ments of the fuel. It bears an indispensable rela- 
tion to the mechanical forces that man now employs, 
for it is the agent which maintains combustion in the 
furnaces of our industries. All the activities of life 
are intimately related to it. When a plant grows, oxy- 
gen is torn from its union with other elements by the 
dominating power of the sun's rays, and energy is 
stored in vegetable tissue. When this tissue is used as 
food the oxygen returns to its former combinations 
through the opportunities offered by the vital pro- 
cesses of the animal, and the hidden forces of the plant 
compounds are thus manifested in a variety of ways. 
The animal labors and man toils and thinks because of 
the energy thus stored and liberated. 

Hydrogen. — This element, which, in a free state, 
is the lightest known gas, is found abundantly in na- 
ture only in combination with other elements. The 
minute quantities which exist in the air are due to 
volcanic action and possibly to decay under certain 
conditions. As a manufactured product, it has an im- 
portant use in producing intense heat and in filling bal- 
loons. Hydrogen constitutes about one -ninth of water 
by weight, and is found in a large number of soil com- 
pounds. It is an essential constituent of vegetable 
and animal tissues, although it exists in the compounds 



16 The Feeding of Animals 

of living organisms in a much smaller proportion than 
carbon or oxygen. Plants obtain it largely from water, 
and it is furnished to the animal body in water and in 
other compounds. 

Nitrogen. — Probably no element has been given 
more attention in its relations to agriculture from the 
scientific and practical standpoints than has nitrogen 
as such and in its compounds. Like oxygen it is an 
invisible, tasteless, and odorless gas which forms in the 
free state a large part of the earth's atmosphere. The 
air has been considered to be approximately 77 per 
cent free nitrogen by weight, but the discovery of the 
new element, argon, which has heretofore passed as 
nitrogen, will slightly modify previous determinations. 

Nowhere outside of the air and the tissues of living 
organisms does nitrogen exist in any form in compara- 
tively large quantities. The soil spaces contain it and 
it is taken into solution in small proportions in all 
natural waters. It is found in the mineral, as well as 
organic compounds of the soil, but in quantities which 
seem insignificant as compared with other elements, 
such as oxygen and silicon. Few agricultural soils 
contain over one -half of one per cent of combined 
nitrogen. Minute quantities of its compounds exist in 
the atmosphere which are being constantly carried to 
the soil in rain-water and as constantly replaced by the 
ammonia from decomposing animal and vegetable mat- 
ter and by the products of the oxidation of nitrogen 
through electrical action and combustion. Notwith- 
standing this comparatively small supply of nitrogen 
compounds, they play a prominent part in agriculture, 



Nitrogen 17 

both commercially and physiologically. The nitrogen 
balance of the farm must be carefully considered both 
by the crop producer and by the cattle feeder. 

Nitrogen compounds are especially important be- 
cause the available supply is often dangerously near 
the demand or even below it. The nitrogen found in the 
air is inert for animal uses, and is ignored by a large 
majority of plants. Much of that in the soil is also 
unavailable. Moreover, its immediately useful com- 
pounds on the farm are constantly subject to loss, — 
first by processes of fermentation which the farmer 
cannot wholly prevent, and second by soil losses which 
are to some extent beyond control. Many of the com- 
mercial products of the farm also cany away much 
nitrogen. The sources of supply to balance this outgo 
are the nitric acid and ammonia of the rainfall, the 
free nitrogen captured by legumes and whatever comes 
from purchased fertilizers and foods. These facts relate 
primarily to plant production, but they also sustain an 
essential relation to the maintenance of animal life and 
cannot be ignored in a rational and w r ell- directed sys- 
tem of animal husbandry. 

Physiological^, the nitrogen compounds stand in 
the front rank. They are necessary building material 
for the fundamental tissues of the animal and are inti- 
mately related to the prominent chemical changes which 
are involved in growth and in the maintenance of life. 
It is safe to assert, too, that variations of these com- 
pounds in the food may have an important influence 
on the character of the body structure or on the 
amount of a particular product. 

B 



18 The Feeding of Animals 

As a result of these conditions which relate to the 
supply of useful nitrogen and to its important role, we 
find that it has assumed a prominent place in com- 
merce. It is the most costly ingredient of fertilizers, 
and the value of commercial cattle foods is sometimes 
based almost wholly upon their content of this element. 
For these reasons, the control, even though only par- 
tial, which the farmer may now assume over the in- 
come and outgo of the nitrogen compounds valuable 
to agriculture is a triumph of modern science, and an 
important feature of rural economy. 

Sulfur is a common and familiar substance. As an 
element it is not widely distributed in nature, but its 
compounds are found in all soils and natural waters, 
and in all the higher forms of animal and vegetable life. 
We know it as "brimstone" when fused in sticks and 
as "flowers of sulfur" when in a finely divided form. 
Its most common commercial compounds are sulfuric 
acid and the sulfates of potash, soda, lime and mag- 
nesia. This element is an essential part of some of 
the most important tissues of the animal body, and is 
supplied in food in the form of the sulfates and in its 
proteid combinations. 

Phosphorus occupies an important place among the 
elements of nutrition. In the uncombined form it does 
not exist in nature, as that found in laboratories is 
produced only by chemical means. Its compounds are 
found everywhere. The phosphates of calcium, mag- 
nesium and iron are widely distributed in soils and 
large deposits of calcium phosphate are known, from 
which is obtained the crude phosphatic rock that serves 



Other Elements 19 

as a basis for the manufacture of commercial fertilizers. 
All feeding stuffs in their natural forms contain phos- 
phorus, either as phosphates, or as combined in certain 
nitrogen compounds which stand in close relation to 
the vital processes. It is distributed in the flesh of 
animals, and combined with lime constitutes a large 
part of bone. 

Chlorine, which is a constituent of common salt, is 
essential to the nutrition of the animal. At ordinary 
temperatures it is, in the free state, a greenish -colored, 
disagreeable gas. When combined with hydrogen it 
forms hydrochloric acid, a compound which is necessary 
to th3 digestion of food. Any ordinary mixed ration 
contains this element in a quantity sufficient for the 
animal's needs. 

Potassium combined with oxygen and hydrogen 
gives us the caustic potash of the market. The ashes 
of all plants contain this element, a familiar illustra- 
tion of this fact being the potassium carbonate leached 
from wood ashes by hot water in the old-fashioned way 
of making soft soap. The saleratus formerly used in 
bread -making is a potassium compound. This element 
is found in the flesh of animals, mostly in the form of 
the phosphate, and is abundantly supplied for the pur- 
poses of nutrition by all feeding stuffs that are not 
by-products. 

Sodium is the basal element of common salt, and in 
this form it is very generally supplied to domestic ani- 
mals. In this connection, sodium chloride (common 
salt) is about the only sodium compound we need to 
mention, for this is the one that serves almost wholly 



20 The Feeding of Animals 

as a source of this element to the animal whether it 
is supplied directly as such or is obtained from the 
food. Sodium plays an important part in the diges- 
tion of food, because it is the basis of certain bile 
salts and is concerned in other ways in the digestive 
processes. 

• Calcium, when united with oxygen, forms lime, 
which is one of our commonest commercial articles. 
Large masses of lime rock, or carbonate of lime, exist 
in many parts of the earth's surface, and every soil 
contains more or less of lime compounds. As com- 
pounds of this element are usually found in plants and 
in the milk of all animals, normal food nearly always 
furnishes a supply sufficient to meet the demands of 
animal life. The growing animal makes a generous 
use of lime, because in union with phosphoric acid it is 
the chief building material of the bony framework. 
A deficiency of food lime is sure to cause abnormal 
development of the bony structures. With birds, it 
is especially in demand during egg formation, egg 
shells being mostly a lime compound. 

Iron, one of the elements of living organisms, needs 
no description, because its common properties are fa- 
miliar to every one. Iron rust and iron ore are oxides 
of this element, and when the oxygen is removed from 
these, we have the bright gray metal of commerce. 
Though taken up by plants and animals in small quan- 
tities only, iron is absolutely essential to their growth 
and welfare, but because of its abundance the impera- 
tive character of the demand is never realized in ordi- 
nary experience. 



The Elements in Plants 21 

PROPORTIONS OF THE ELEMENTS IN PLANTS AND 

ANIMALS 

The facts which have been reviewed concerning the 
elements out of which the tissues of plants and animals 
are built are properly supplemented by a statement of 
the proportions in which these are found in living or- 
ganisms. This information is necessary to an under- 
standing of the relations of supply and demand which 
exist between the vegetable and animal kingdoms and 
the raw materials of the inorganic world. 

In Plants. — It is estimated by a German scientist, 
Knop, that if all the species of the vegetable kingdom, 
exclusive of the fungi, were fused into one mass, the 
ultimate composition of the dry matter of this mixture 
would be the following: 

Per cent 

Carbon 45 

Oxygen .... 42 

Hydrogen 6.5 

Nitrogen 1.5 

Mineral compounds ( ash) 5 

The composition of various single species or of parts 
of a plant, such as the fruit or straw, shows consid- 
erable variations from these average figures: 

Carbon Oxygen Hydrogen Nitrogen (Ash) 

Clover hay 47.4 37.8 5. 2.1 7.7 

Wheat kernel 46.1 43.4 5.8 2.3 2.4 

Wheat straw 48.4 38.9 5.3 .4 7.0 

Fodder beets 42.8 43.4 5.8 1.7 6-3 

Fodder beet leaves 38.1 30.8 5.1 4.5 21.5 



22 The Feeding of Animals 

Carbon constitutes a larger proportion of the dry 
substance of plants than any other element, and there 
is certainly no species that is an exception to this rule. 
Oxygen stands next in order, followed by hydrogen, 
and then nitrogen. It is an important fact in the 
economy of nature that those elements which, on the 
average, make up 93.5 per cent of the dry matter of 
plants have as their main source either the atmosphere 
or water. Only a small percentage of the dry matter of 
the farmer's crops is drawn from the soil, and it there- 
fore follows that it is this small proportion of the mass 
of matter that makes up the inorganic world which 
sustains the most important economic and financial 
relations to the farmer's business. 

The elements of the ash vary somewhat in different 
plants. For illustration, their proportions in the dry 
matter of the maize plant in bloom are given in this 
connection: 

Per cent 

Phosphorus 26 

Silicon 51 

Sulfur 07 

Chlorine 29 

Potassium 1.78 

Sodium 19 

Calcium 72 

Magnesium 39 

Iron 10 

Oxygen combined with the above 1.73 

Total per cent 6.04 

In animals. — We are not ignorant of the propor- 
tions of the chemical elements in the bodies of our 



Proportions of Chemical Elements 23 

larger animals. Lawes and Gilbert, of England, and 
the Maine Experiment Station, in this country, have 
made analyses of the entire bodies, or nearly so, of 
steers and other domestic animals. These results, com- 
bined with our knowledge of the constitution of the 
compounds of the animal tissues, enable us to calcu- 
late very closely the proportions of carbon and other 
elements in the entire body of an ox: 

Fat ox Two steers, 2 yrs. old 

Lawes and Gilbert Maine Station 
Per cent Per cent 

Carbon 63 60 

Oxygen 13.8 14.1 

Hydrogen 9.4 9. 

Nitrogen 5. 5.8 

Mineral compounds (ash) . 8.8 11.1 

As the proportion of carbon is much larger in the 
fats than in the other compounds of the animal body, 
it is easy to see that the ultimate composition of the ox 
would vary with his condition, whether lean or very fat. 
The figures given suffice to show, however, that ani- 
mals, like plants, contain much more carbon than of 
any other element, and that the quantities of the re- 
maining elements stand in the same order in the plant 
and in the animal, the striking differences being the 
greater proportion of ox y gen in the former and of 
carbon and nitrogen in the latter. The plant and ani- 
mal are alike, therefore, in consisting chiefly of those 
elements which are derived from air and water. Car- 
bon, oxygen and hydrogen constitute from 83 to 86 per 
cent of the bodies of fat oxen and steers, raw materials 
which nature supplies without cost to the farmer, leav- 



24 The Feeding of Animals 

ing less than one-sixth of the animal to be bnilt from 
elements that have, in part, a commercial value for 
crop production, which is the fundamental considera- 
tion in animal husbandry. 

As has been stated previously, one of these ele- 
ments, which in its various compounds bears a market 
value, is nitrogen. The others having commercial im- 
portance belong to what is termed the ash of the plant 
or animal. For this and other reasons it is desirable 
to consider the elements found in the ash or mineral 
portion of the animal body. We will return for this 
information to the analysis of a fat ox made by Lawes 
and Gilbert. These investigators found that the ash, 
constituting 8.8 per cent of the dry substance of the 
entire body, was made up as follows: 

Per cent 

Phosphorus 1.53 

Calcium 2.80 

Potassium . • . - .26 

Sodium 20 

Magnesium 07 

Oxygen, combined with the above 3.29 

Silicon, sulfur 65 

8.80 

Of the elements other than oxygen which appear in 
the ash, phosphorus and calcium take a leading place as 
to quantity, although sulfur, potassium and sodium are 
essential, even if present in relatively small amounts. 
Phosphorus, potassium and calcium have a commercial 
prominence in their agricultural relations, a fact which 
is to be considered chiefly in their uses as plant -foods. 



CHAPTER IV 

THE COMPOUNDS OF ANIMAL NUTRITION 

The animal body consists primarily of elements, 
but we ordinarily regard it as made up of compounds. 
These are groups of elements united in such fixed and 
constant proportions that they have as uniform proper- 
ties, under given conditions, as the elements themselves. 
In discussing the composition and uses of cattle foods 
and the structure, composition and functions of the 
animal as an organism, we refer chiefly to the com- 
pounds of carbon rather than to carbon itself. To be 
sure, the investigator of the problems of nutrition often 
conducts his researches and formulates his conclusions 
with reference to the elements, but when the informa- 
tion he secures reaches the language of practice, we 
speak of albuminoids, carbohydrates and fats. Com- 
merce recognizes these compounds also. It is necessary, 
therefore, for the student of animal nutrition, whether 
as a scientist or as one who would thoroughly under- 
stand the art of feeding, to become well informed about 
those substances that in various proportions form the 
organized structure of plants, and that furnish not 
only the energies that are manifested by animal life, 
but all the materials out of which the animal tissues 
are built. 

(25) 



26 The Feeding of Animals 

CLASSES OF MATTER 

Before passing to a consideration in detail of the 
proximate constituents of plants and animals, it is de- 
sirable to reach a clear understanding of certain broad 
divisions into which we classify all matter, either living 
or dead, which has been organized by the vital forces 
of the various forms of life. 

One of the most common and familiar phenomena 
of the physical world is the destruction of vegetable or 
animal matter by combustion, with the result that only 
a small portion of the original material is left behind 
in visible and solid forms. Fuel, such as wood or coal, 
is largely consumed when ignited, and we have as a 
residue the ashes. If we incinerate hay, corn or wheat 
we get the same result. The gradual decomposition of 
exposed dead vegetable matter that occurs in warm 
weather is a process essentially similar to the com- 
bustion of fuel, only more prolonged. In view of 
these facts, it is customary to classify all the tissues of 
plants and animals into the combustible and incombus- 
tible portions, the former being that part of the ignited 
or decayed substance which disappears in the air as 
gases, and the latter the residue or ash. It should be 
well understood that combustion does not involve a loss 
of matter; only a change into other forms. If we w r ere 
to collect the gases which pass off from a stick of wood 
that is burned, consisting mostly of carbon dioxid, 
vapor of water, ammonia and, perhaps, certain other 
compounds of nitrogen, we would find that their total 
weight, plus that of the ash residue, is even greater 



Classes of Matter 27 

than that of the dry wood, because the carbon and the 
hydrogen of the wood have taken to themselves from 
the air, during the combustion, an increased amount 
of oxygen. The carbon, oxygen, hydrogen and nitrogen 
of the plant or animal tissue belong to the combusti- 
ble portion, although small amounts of two of these 
elements are found in the ash, as it is usually esti- 
mated. The remainder of the fifteen elements previ- 
ously named are supposed to appear wholly in the ash. 
The relation in quantity of the combustible and in- 
combustible parts of vegetable and animal dry matter 
is illustrated below: 

Combustible Incombustible 
(Ash) 
Per cent Per cent 

Clover hay 92.8 7.2 

Potato tubers 95.5 4-5 

Maize kernel 98.3 1.7 

Wheatkernel 98. 2. 

Body of fat ox 91.2 8.8 

The significance of these facts in their relation to 
cattle feeding is, that the chemical change which we 
call combustion is one of the phenomena of animal nu- 
trition. Substances which may suffer either slow or 
rapid oxidation outside the animal may undergo com- 
plete or partial combustion in the animal; or, stated in 
another way, the part of the plant which "burns up" 
in the fireplace or crucible is the part which in general 
undergoes the same change within the animal organism 
in so far as the food is digested. 

The terms combustible and incombustible are less 
used, perhaps, than two others, which represent prac- 



28 The Feeding of Animals 

tically the same divisions of plant or animal substance; 
viz., organic and inorganic. In chemical literature, 
the portion of a plant or animal which suffers combus- 
tion is called the organic, and the ash is known as the 
inorganic part. These terms are evidently based upon 
the erroneous assumption that the compounds which 
burn and break up into simpler ones are peculiarly 
those which sustain necessary and vital relations to life, 
and are formed through the functions of living organ- 
isms. To be sure, the dry substance of the plant is 
organized chiefly by building up compounds of carbon, 
oxygen, hydrogen and nitrogen, which suffer combus- 
tion; but compounds of sulfur, phosphorus, chlorine, 
potassium, sodium and calcium are also constant and 
essential constituents of the juices and tissues of the 
plant and animal; and, although the latter elements 
may finally wholly appear in the incombustible part 
or ash, they have, nevertheless, sustained in other com- 
binations important relations to nutrition and growth. 
It is true, however, that the portion of a food material 
which is commonly spoken of as organic embraces those 
compounds that furnish practically all the energy which 
is utilized by animal life and much the larger part of 
the building material. 

THE CLASSES OF COMPOUNDS 

The known compounds that belong to life in all its 
forms are almost innumerable, and doubtless many are 
yet to be discovered. These sustain a variety of re- 
lations to human needs, some serving as food, some 



Classes of Compounds 29 

as medicine and some in the arts. It is fortunate 
that comparatively few must be considered in dis- 
cussing the science and art of cattle -feeding. More- 
over, it is convenient that the compounds which play 
a leading part in animal nutrition are designated, es- 
pecially for practical purposes, in classes rather than 
singly, even though this custom tends to more or less 
looseness of expression and definition. 

The same classification is used for the compounds of 
both the vegetable and animal kingdoms, and it is now 
customary to divide them into the following groups : 

Water, 

Ash (mineral compounds), 
Protein (nitrogenous compounds), 
Carbohydrates (and related bodies), 
Fats (or oils). 

In this instance, accuracy is sacrificed to conven- 
ience. The class names have come to be regarded, 
more or less, as representing entities having fixed prop- 
erties and functions, whereas each class contains numer- 
ous compounds differing widely in their characteristics 
and in their nutritive value and office. Moreover, these 
terms have a variable significance as used under differ- 
ent conditions. No one of them except water uniformly 
represents just the same mixture of compounds when 
applied to unlike feeding stuffs. 

Before passing to a detailed description of these com- 
pounds, singly or in groups, it will be well to gain a 
clear understanding of the relation which the fifteen ele- 
ments mentioned sustain to these classes of substances. 
This can be seen most readily by a tabular display: 



30 



The Feeding of Animals 



All vegeta 
ble or ani 
mal matter . 



Incombustible 
or inorganic 
matter . . . 



Water 



Ash 



Combustible 
or organic 
matter . . . 



Protein 



f Oxygen 
\ Hydrogen 

' Oxygen 
Sulfur 
Chlorine 
Phosphorus 
Silicon. Fluorine 
Potassium 
Sodium 
Calcium 
Magnesium 
Iron 
Manganese 



Carbon 

Oxygen 

Hydrogen 

Nitrogen 

Sulfur (generally) 

Phosphorus (sometimes) 

Iron (in a few cases) 



Carbohydrates f Carbon 
and fats . . 1 Oxygen 

L Hydrogen 



The ash, which, on the average, constitutes about one- 
twentieth of the plant, and never more than one -tenth 
of the animal, may contain thirteen of the fifteen 
elements, while the larger proportion of living matter 
consists mostly of the compounds of three or four ele- 
ments, in no case of more than six or seven. From 
this point of view, it becomes strikingly evident that 
the dominant elements of life, quantity alone consid- 
ered, are those derived from the air and water. 



WATER 



Water fills a very important place in agriculture. 
It is everywhere present, generally in some useful way. 
All plant substance, all animal tissue, foods and nearly 



Water in Organic Substance 31 

all the material things with which man comes in contact 
in his daily life are made up of more or less water, or are 
associated with it. Sometimes this is very evident, as 
with green plants or juicy fruits. It is not so evident 
with straw and cornmeal. If, however, we submit 
almost any substance, no matter how dry it may 
appear, except perhaps, glass and metals, to the heat 
of an oven at 212° F., we find that a material loss 
of weight occurs: and if we so arrange that whatever 
is driven off is first drawn through some substance 
that entirely absorbs the water which has been vapor- 
ized, we learn that the decrease in weight is nearly all 
accounted for by the water thus collected. 

This fact suggests to us the chemist's way of deter- 
mining the proportion of water which any particular 
material contains. He weighs out a certain amount 
of the substance and then keeps it in an oven at 
212° F. for five hours perhaps, after which it is re- 
weighed. The difference in the two weights, or the 
loss, is assumed to be all water, and the percentage in 
the original substance is easily calculated. That por- 
tion of the material which is left behind after the water 
is evaporated, we call the dry substance. 

Water is associated with plant and animal tissues 
in two ways, hygroscopically and physiologically. It 
is easy to illustrate the former way by an object lesson. 
If an ounce of cornmeal were to be dried in an oven 
as described, it would, as stated, lose in weight. If it 
were subsequently allowed to remain exposed in the 
open air in a barn or out of doors, it would return 
quite or nearly to its original weight. The loss would 



32 The Feeding of Animals 

be due to water driven out, and the gain to water ab- 
sorbed from the atmosphere, which we call h} r groscopic 
moisture. 

All solids attract moisture up to a certain propor- 
tion, which varies with the substance and with the 
conditions that prevail. The surfaces of the particles 
of matter are ordinarily covered with a thin film of 
water, which is thicker on a cold, wet day than on a 
warm, dry day, and so the same quantity of hay or 
grain weighs less at one time than at another, because 
the percentage of hygroscopic water varies. An equi- 
librium will always be established between the attrac- 
tion of a substance for moisture and the tension of the 
vapor of water in the surrounding air, which accounts 
for the effect of temperature and of the degree to 
which the air is saturated with water vapor. As 
all substances do not have the same attraction for 
moisture, therefore, under similar atmospheric condi- 
tions, one feeding stuff may retain more water than 
another. 

Water that is held physiologically is that which is 
a constant and essential part of living organisms, in 
which relation it is necessary to life and performs 
certain important functions. These functions are of 
three kinds: (1) The presence of water in the tis- 
sues of plants and animals gives them more or less 
firmness or rigidity combined with elasticity; (2) 
water acts as a food solvent; (3) water is the great 
carrier of food materials and of waste products from 
one part to another of the vegetable or animal or- 
ganism. 



Water in Plants 33 

Water in living plants. — Water constitutes a large 
proportion of the weight of all living plants, especially 
during the period of active growth. The cured hay, as 
any farmer's boy knows, weighs much less than did the 
green grass when it was cut, and this loss in weight is due 
almost wholly to evaporation of water from the tissues 
of the plant under the influence of the sun and wind. 
This water, which is contained in the tubes and inter- 
cellular spaces of the stalk or leaf, is exactly the same 
chemical compound as pure water found anywhere else, 
and has no more value for the animal, excepting that 
it is pure and is not subject to the contamination which 
sometimes occurs in streams and wells. There is no 
such thing as the so-called natural water of plants, and 
which has a peculiar nutritive value or function. Vege- 
tation water should be distinguished from sap or plant 
juice. Sap is more than water; it is water holding in 
solution certain substances such as sugars and min- 
eral salts. When the plant is dried, these soluble com- 
pounds do not pass off, but remain behind as part 
of the dry matter. 

The proportion of water in plants varies greatly in 
different species, and in the same species according to 
the stage of growth or the surrounding conditions. 
These facts have more importance than is generally 
recognized, because the food value of vegetable sub- 
stances is influenced by the proportion of dry matter. 
It is always necessary to know the percentage of water 
in a green plant before we can estimate its worth for 
feeding purposes. 

The variations in water content of the living tissues 



34 The Feeding of Animals 

of different species of plants or parts of plants is well 
illustrated by the following figures: 

Water in green plants 

Per cent 

Pasture grass (mixed) 80 

Timothy grass 61.6 

Oats (fodder) 62.2 

Rye (fodder) 76.6 

Sorghum (fodder) 79.4 

Fodder corn, dent, kernels glazed 73.4 

Fodder corn, flint, kernels glazed 77.1 

Red clover 70.8 

Alfalfa 71.8 

Horse bean 84.2 

Potatoes (tubers) 78.9 

Beets (mangels) 90.9 

Turnips 90.5 

Immature plants contain more water than older or 
mature ones. Young pasture grass is more largely 
water than the same plants would be after the seed is 
formed. TLis iact is consistent with the very rapid 
transference of building material during the active 
stages of growth. Analyses of samples of timothy 
grass cut at the Maine State College in 1879, and at 
the Pennsylvania State College in 1881 show the 
marked inthience of the stage of growth upon the 
water content of the living plant: 

Maine State College 
Timothy Percentage of water 

Nearly headed out 78.7 

In full blossom 71.9 

Out of blossom 65.2 

Nearly ripe 63.3 



Water in Plants 35 

Pennsylvania State College 
Percentage of water 
Highly No 

manured manure 

Cut June 6, heads just appearing 79.7 76.5 

Cut June 23, just beginning to bloom 69.7 69.1 

Cut July 5, somewhat past full bloom 61.4 60 

What is true of timothy is probably true of all 
forage crops iu the perfectly fresh state. We have 
here au explanation of the difficulty of curing earty 
cut grass. When the farmer begins haying, at least 
two drying days are needed in order to secure a 
product that will not ferment in the mow, while later 
in the season, grass cut in the morning may be safely 
stored in the mow before night. At the Maine State 
College in 1880, immature timothy grass lost 56.7 per 
cent weight in curing and the ripe grass only 12.9 
per cent. The extreme succulence of immature corn 
and other crops previous to the formation of seed, is a 
fact. which the dairyman who feeds soiling crops must 
consider if he would uniformly maintain a ration up 
to the desired standard. 

The proportion of water in plants is influenced also 
by the lack or excess of soil moisture. The soil and 
not the atmosphere is the source of supply of vegeta- 
tion water, which, taken up by the roots, traverses the 
plant and passes into the atmosphere through the 
leaves. If the supply is abundant, the tissues are 
constantly fully charged, but if, by reason of drought, 
the soil becomes very dry, the outgo of water by evap- 
oration may exceed the income. What farmer has not 
seen his corn with rolled leaves during an August 
drought ! The vegetation water had fallen below the 



36 The Feeding of Animals 

normal, or below what was necessary to maintain the 
tissues in their usual condition of rigidity. 

This leads to the observation that the water in a 
growing plant is that which is in transit from the soil 
to the air. This liquid stream enters the plant with 
its load of building materials, takes into solution the 
compounds elaborated in the leaves and aids in trans- 
porting them to the points of rapid growth, finally 
passing into the air from the surface of the foliage. 
Throughout the entire growing season, the plant acts 
as a pump, drawing from below through the roots the 
water which it needs for various purposes, and dis- 
charging it into the air. It was found that in Wis- 
consin 309.8 tons of water was evaporated by the 
plant for each ton of dry matter in the crop. Four 
tons of dry matter per acre is not an unusual product 
with maize, requiring 1,239.2 tons, or 10.4 inches of 
water for its growth, the equivalent of about five -eigh- 
teenths of an average annual rainfall. This is a fact of 
great significance to the stock feeder. His success be- 
gins with proper husbanding of the plant -food resources 
of the farm, of which water is an important factor. 

Water in feeding stuffs. — Cattle foods, whether in 
the green or air -dry condition, always contain more or 
less water. The proportion is greatly variable, depend- 
ing upon several factors. With the green foods, the 
range of percentages is similar to that of the living 
plants previously noted. As, however, forage plants 
are used at varying lengths of time after cutting, and as 
a loss of moisture begins immediately after the plant is 
severed from its source of water supply, the amount of 



Water in Feeding Stuffs 37 

dry matter in a green cattle food is somewhat uncer- 
tain, unless a water determination is made in the ma- 
terial exactly as it is fed. In all experimental work 
this precaution is necessary to accuracy. Roots and 
potatoes contain a large proportion of water, which, 
owing to their structure, is slowly evaporated. In a 
cool, moist cellar, their water content will remain prac- 
tically unchanged for a long time. In a warm, dry room 
evaporation occurs and they shrivel and lose weight. 

The water content of air -dry foods varies with the 
condition in which they were stored, the length of time 
after storage and the percentage of moisture in the air. 
Early cut hay often goes to the barn less perfectly 
cured than the late cut, and all hay dries out more 
than is generally realized during the first few months 
of storage. Concerning these points, the writer has ob- 
tained data through experiments at the Maine State and 
Pennsylvania State Colleges. Fourteen lots of hay, some 
early cut and some late cut, were weighed when stored 
and after remaining in the barn for several months. 
The results follow: 









Early cut 






Late cut 






As 
stored 


After 
several 
months 


Per cent 
loss 


As 
stored 


After 
several 
months 


Per cent 
loss 


Timothy, 


1881.. 


. 3634 


2307 


36.5 


4234 


3390 


19.9 


<< 


1882.. 


. 3634 


2556 


29.7 


3802 


3168 


16.7 


tt 


1881.. 


. 5000 


3922 


21.6 


5270 


4035 


23. 


t< 


1882.. 


. 3570 


3037 


14.9 


4017 


3413 


15. 


Clover, 


1882.. 


. 2110 


1215 


42.4 


1520 


1130 


25.6 


Timothy, 


1888.. 


. 2815 


2470 


12.2 


2790 


2420 


13.3 


<< 
Ave 


1889.. 


. 5070 


4225 


16.6 


6208 


5086 


18.1 



General average loss, 22.2. 



38 The Feeding of Animals 

It is probable that hay seldom loses less than one- 
eighth of its weight during storage, and often much 
more. 

As illustrating the variations in the proportions of 
water in hay due to changes iu air moisture, reference is 
made to observations by Professor Atwater. He found 
that dry hay hung in bags in a barn varied in water con- 
tent between 7.5 per cent and 13.6 per cent during the 
months of May, June and July. Hay in large masses 
would change less, but would be affected, doubtless, by 
long periods either of very dry weather or very wet. 

The proportion of moisture in coarse foods and 
grains has much to do with their preservation in a 
sound condition. New hay and grains when packed in 
large masses are subject to fermentations, which injure 
their quality and diminish their food value. This is 
due to the fact that sufficient moisture is present to 
allow the growth of low forms of life with certain at- 
tendant chemical changes. Feeding stuffs containing 
20 per cent or more of water, — and this is likely to 
be the case with clover, rowen, field -cured cornf odder 
and stover, new oats and new corn, — when stored in 
large quantities are afmost certain to heat and become 
musty or moldy, always involving a loss of nutritive 
value, a result wholly due to the large proportion of 
water present. 

Water in the animal. — Water is an important and 
abundant constituent of animal organisms, from the 
lowest to the highest forms. The blood, which is from 
one -thirtieth to one -twentieth the weight of the bodies 
of farm animals, is at least four -fifths water, while the 



Water in Animals 39 

soft tissues have been found to contain from 44 per 
cent to 75 per cent, according to the species and con- 
dition of the animal. The most extensive and com- 
plete analyses so far made of the entire bodies of 
animals were performed by Lawes and Gilbert at Roth- 
amsted, England. In this country four steers were 
analyzed at the Maine Experiment Station, and in 
the study of human nutrition problems many determi- 
nations of water have been made in the carcasses of 
bovines, swine, sheep, poultry and game. The figures 
are as follows: 

Water in entire body 

Per cent 

Ox, well-fed, Lawes & Gilbert 66.2 

Ox, half fat, Lawes & Gilbert 59. 

Ox, fat, Lawes & Gilbert 49.5 

Steer, 17 months old, medium fat, M. E. S 59. 

Steer, 17 months old, medium fat, M. E. S 56.3 

Steer, 27 months old, fat, M. E. S 51.9 

Steer, 27 months old, fat, M. E. S 52.2 

Calf, fat, Lawes & Gilbert 64.6 

Sheep, lean, Lawes & Gilbert 67.5 

Sheep, well-fed, Lawes & Gilbert 63.2 

Sheep, half fat, Lawes & Gilbert 58.9 

Sheep, fat, Lawes &'_ Gilbert 50.9 

Sheep, very fat, Lawes & Gilbert 43.3 

Swine, well-fed, Lawes & Gilbert 57.9 

Swine, fat, Lawes & Gilbert 43.9 

Chicken, flesh 74.2 

Fowl, flesh 65.2 

Goose, flesh 42.3 

Turkey, flesh 55.5 

It is very evident that, in general, considerably more 
than half of the weight of the bodies of our domestic 



40 The Feeding of Animals 

animals consists of water, the limits observed in all 
species and conditions here mentioned being 42.3 per 
cent and 67.5 per cent. 

The percentage of water varies with the species, age 
and condition. Swine carry a notably small proportion. 
The calf's body, even though fat, is comparatively 
watery. It is very noticeable that with oxen, sheep and 
swine the lean animals contain a much larger proportion 
of water than the fat. This does not mean that in the 
process of fattening the fat is substituted for water, 
and so expels it from the organism, but that the in- 
crease has a much smaller percentage of water than 
the body in its original lean condition. This is well 
illustrated by the data from two independent investi- 
gations at Rothamsted and at the Maine Experiment 
Station. The former investigation showed that when 
swine, sheep and oxen are fattened the increase con- 
tained from 20 per cent to 24 per cent of water, this 
being half the proportion found in the entire bodies of 
the lean animals. The Maine Station results established 
the fact that in the increase of two steers from the age 
of 17 months to 27 months, during which time a fat- 
tening ration was fed, there was 42 per cent of water, 
the bodies of the younger steers having 58.2 per cent. 
It is a common remark among unscientific people that 
beef from mature animals " spends " better than that 
from young, the same observation being made in com- 
paring lean and fat beef. Modern investigation shows 
clearly that the reason for this lies partly in the differ- 
ence in water content. Dry matter, and not water, is 
the measure of food value. 



The Ash Contents 41 

ASH 

The ash or mineral part of plants or animals occu- 
pies a minor place in the discussions which pertain to 
the principles and problems of animal nutrition. Much 
is said and written about the carbon compounds of 
living organisms, but the compounds of the mineral 
world, in their relation to foods and to the processes of 
growth, are generally passed by with brief comment, 
much less than would be profitable. It is certainly 
desirable to gain a clear understanding of the combi- 
nations, distribution and functions of these bodies. 
Their importance as necessary constituents of foods 
and animals is no less than pertains to the carbon 
compounds, although their scientific and commercial 
prominence as related to animal nutrition is much 
less. 

As previously stated, the mineral portion of a plant 
or animal is measured by the ash or residue after com- 
bustion, the principal ingredients of which are the 
following : 

Acids Bases 

Hydrochloric acid HC1. Potash K 2 

Sulfuric acid H 2 S0 4 Soda Na 2 

Phosphoric acid H 6 P 2 8 Lime CaO 

Silicic acid Si0 2 Magnesia MgO 

Carbonic acid C0 2 Iron oxid Fe 2 3 

Other mineral compounds are found in the various 
forms of vegetable life, but those mentioned are all 
that we need to discuss at length. 

The acids and bases do not exist in the ash as 



42 The Feeding of Animals 

shown, but they are united to form salts, and so we 
have the chlorides, sulfates, phosphates, and carbon- 
ates of potassium, sodium, calcium and magnesium. 
These are nearly all familiar objects in common life, 
as, for instance, sodium chloride (common salt), potas- 
sium chloride (the muriate of potash of the market), 
potassium sulfate (the sulfate of potash of the market), 
calcium sulfate (of which gypsum or land plaster is 
composed), calcium phosphate (burned bone is chiefly 
this compound), potassium phosphate (a compound of 
phosphoric acid and potash found chiefly at the drug- 
gist's) and calcium carbonate (limestone). It should be 
remembered that the compounds in the ash are not 
necessarily those of the plant or animal. During the 
process of ignition, there is a rearrangement of the 
acids and bases, so that phosphoric acid which was 
combined with potash in the plant may be united 
with lime in the ash. Much of the lime in the ash 
is in union with carbonic acid, which in the plant 
may have been associated with vegetable acids, such 
as oxalic and tartaric, and part of the sulfur and 
phosphorus of the ash comes from the nitrogen com- 
pounds. 

These salts differ greatly in their properties. Some 
are soluble in water, others are not. To the former 
class belong all the chlorides, and the potassium and 
sodium sulfates and phosphates. The normal phos- 
phates of calcium and magnesium are insoluble in 
water, but soluble in various acids. These facts are 
important in showing what salts are in solution in the 
plant and animal juices, and what effect leaching with 



Ash in Plants 43 

water or other solvents would have upon the inorganic 
portion of cattle foods. 

The mineral compounds of plants. — All plants and 
feeding stuffs contain mineral compounds, which are 
important in this connection because, excepting com- 
mon salt, they are the only source of the mineral con- 
stituents of the animal body. These are held in the 
plant tissue chiefly in three ways; in solution in the 
juices, in crystals in the cells and as incrustations in 
the cell walls. With the exception of oxygen, sulfur 
and phosphorus, no ingredient of the ash has sus- 
tained, so far as known, a structural relation to plant 
growth. When the fresh plant substance is reduced to 
an air- dry condition, the salts in solution become de- 
posited in the tissues as solids. The mineral matter 
of plants and feeding stuffs is by no means uniform 
in composition and quantity, even in the same species 
or class of materials, although in some grains there is 
a fair degree of similarity in this respect. Certain 
factors cause variations, such as species, stage of 
growth, fertility, the part of the plant, manner of 
curing or treatment of a feeding stuff and changes due 
to manufacturing processes, and the variations which 
exist pertain not only to the amount of ash but also 
to its composition. 

Variations due to species. — Different species of 
plants, and consequently different feeding stuffs, are 
greatly unlike in their content of mineral matter. The 
figures below illustrate this fact, further confirmation 
of which may be had by consulting the table in the 
appendix: 



44 The Feeding of Animals 

No of Per cent 

analyses ash 

Mixed grasses 106 7. 

Timothy grass 9 6.8 

English ray grass 11 12.1 

Red clover, in bloom 113 6.9 

White clover, in bloom 4 7.3 

Seradella, in bloom 3 9.8 

Buckwheat 17 8.2 

Potatoes 59 3.8 

Sugar beets 149 3.8 

Mangel-wurzel 19 7.6 

Turnips 32 8. 

Carrots 11 5.8 

Winter wheat 110 2. 

Oats 57 3.1 

Summer barley 57 2.6 

Maize 15 1.4 

Peas 40 2.7 

Field beans 19 3.6 

It is important to know that these variations pertain 
not alone to the quantity of ash but to the proportions 
of compounds which it contains : 



The mineral 


compounds 


ofp> 


lants and feeding stuffs 








(per 


cent in 


the dry matter) 










Pot- 
ash 


Soda 


Lime 


Mag- 
nesia 


Iron 
oxide 


Phos- 
phoric 
adid 


Sul- 
furic 
acid 


Silica 


Chlor- 
ine 


Mixed grasses.. 


....1.86 


.26 


1.11 


.48 


.11 


.50 


.36 


2. 


.43 




...2.37 


.12 


.55 


.22 


.06 


.80 


.19 


2.19 


.35 


Redcloverin bloom2.21 


.13 


2.39 


.75 


.07 


.66 


.22 


.18 


.26 




....1.57 


.53 


2.21 


.69 


.15 


.94 


.54 


.33 


.31 


Alfalfa 


....1.74 


.13 


3. 


.36 


.14 


.63 


.42 


.70 


.22 




...2.54 


.19 


3.32 


1.09 


.12 


.50 


.30 


.09 


.06 


Roots 






















...2.27 


.11 


.10 


.19 


.04 


.64 


.25 


.08 


.13 




....2.03 


.34 


.23 


.30 


.04 


.47 


.16 


.09 


.18 




...3.96 


1.23 


.28 


.83 


.06 


.65 


.23 


.15 


.75 


Turnips 


....3.64 


.79 


.85 


.30 


.06 


1.02 


.90 


.15 


.41 




...2.02 


1.16 


.62 


.24 


.05 


.70 


.35 


.13 


.25 



Ash in Plants 45 

Phos- Sul- 

Pot- Mag- Iron phoric furic Chlor- 

Grain ash Soda Lime nesia oxide acid acid Silica ine 

Winter wheat 61 .04 .06 .24 .03 .93 .01 .04 

Oats 56 .05 .11 .22 .04 .80 .06 1.22 .03 

Summer barley 56 .06 .07 .23 .03 .92 .05 .68 .03 

Maize kernel 43 .02 .03 .22 .01 .66 .01 .03 .01 

Peas 1.18 .03 .13 .22 .02 .98 .09 .02 .04 

Field beans 1.51 .04 .18 .26 .02 1.41 .12 .02 .06 



We cannot fail to observe as we study these figures 
that potash, lime and phosphoric acid are the promi- 
nent mineral compounds of the whole plant, and con- 
sequently it is with them that we find the important 
variations. The true grasses differ from the clovers 
and related plants in containing much less lime and 
greatly more silica, the phosphoric acid and potash not 
being greatly unlike in the two cases. As a source of 
lime, then, the clover hay is superior. Potatoes and 
roots are richer in potash and poorer in lime than are 
the coarse fodders. The grains with hulls contain much 
silica, and those like wheat and corn but little. The 
seeds of the legumes are richer in potash and lime than 
those of the grasses. The maize kernel is especially 
poor in lime. 

The distribution of mineral compounds in the differ- 
ent parts of the plant. — Because the farmer separates 
his crops into grain and straw, and the manufacturer 
goes farther and divides the grain into parts, thus 
modifying the character of feeding stuffs, it is worth 
while to know just how the mineral compounds are 
distributed in the stalk, leaves and fruit, especially 
of the cereal grain plants. A comparison of the straws 
and grains shows striking dissimilarities: 



46 



The Feeding of Animals 



Per cent in ike dry matter 

Phos- Sul- 

Total Pot- Magne- Iron phoric furic 

Wheat ash ash Soda Lime sium oxide acid acid 

Straw 5.4 .73 .07 .31 .13 .03 .26 .13 

Kernel 2. .61 .04 .06 .24 .03 .93 .01 

Oats 

Straw 7.2 2.07 .24 .50 .26 .08 .33 .23 

Kernel 3.1 .56 .05 .11 .22 .04 .80 .06 

Maize 

Straw 5.3 1.93 .06 .58 .30 .12 .44 .28 

Kernel 1.4 .43 .02 .03 .22 .01 .66 .01 

Peas 

Straw 5.1 1.17 .21 1.89 .41 .09 .41 .32 

Kernel 2.7 1.18 .03 .13 .22 .02 .98 .09 



Silica 


ine 


3.62 


.09 


.04 




3.34 


.31 


1.22 


.03 


1.53 


.07 


.03 


.01 


.35 


.29 


.02 


.04 



In the first place, the straws contain more mineral 
matter than the grains. It is very evident also that in 
the straws there is much more potash, lime and silica 
than in the grains, while phosphoric acid in most cases 
exists in larger proportions in the latter. 

The roots and leaves of beets and turnips present a 
striking difference in mineral content: 



Per cent in the dry matter 

Phos- Sul- 

Total Pot- Mag- Iron phoric furic Chlor- 

Sugar beets ash ash Soda Lime nesia oxide acid acid Silica ine 

Roots 3.8 2.03 .34 .23 .30 .04 .47 .16 .09 .18 

Leaves 14.8 3.90 2.05 3. 1.69 .08 .71 .79 1.51 1.26 

Fodder beets 

Roots 7.6 3.96 1.23 .28 .83 .06 .65 .23 .15 .75 

Leaves 15.3 4.71 2.98 1.63 1.46 .22 1. .86 .56 2.45 

Turnips 

Roots 8.0 3.64 .79 .85 .30 .06 1.02 .90 .15 .41 

Leaves 11.6 2.73 1.10 3.83 .46 .18 .85 1.09 .45 1.18 

There appears to be a tendency for mineral com- 
pounds to accumulate in the leaves of plants, and leafy 
plants are, as a rule, those which appropriate these 
most freely. 



Ash in Feeds 47 

The ash of the outside of the stem and of the husks 
of seeds is in relatively large proportions, due sometimes 
to an excess of silica. Husked rice kernels contain not 
over .5 per cent of ash, while the husks contain 39 
per cent or over. 

Influence of manufacturing processes on the ash con- 
stituents. — The cattle food market is abundantly sup- 
plied with the residues from certain manufacturing in- 
dustries, such as milling, brewing and starch produc- 
tion. The most prominent waste product is wheat 
bran. As this is the outside of the kernel, we would 
naturally expect, in view of the previous statements, 
that it would be rich in mineral compounds, and we 
find such to be the case. The wheat kernel contains 
about 2 per cent of ash, wheat bran about 6 per 
cent and wheat flour about .5 per cent. Bran may 
become, therefore, an important source of mineral com- 
pounds in the ration. In brewing, the kernels of barley 
are subjected to a leaching process, which results in 
taking out the soluble mineral salts, chiefly the salts of 
the alkalies, potash and soda, leaving behind, in part, 
the compounds of lime and magnesia. This fact is 
made clear by comparing the analysis of the ash of 
barley with that of brewer's grain: 

Partial composition of ash (per Gent) 

Mag- Phos. 
Potash Soda Lime nesia acid 

Summer barley 56 .06 .07 .23 .92 

Brewer's grains 15 . — .64 .45 1.69 

As a source of phosphoric acid and lime the brew- 
er's grains are more efficient, pound for pound, than 



48 The Feeding of Animals 

the original barley grains. Much the same thing oc- 
curs in the manufacture of starch and glucose from 
the maize kernel, as in brewing, for the ground grains 
are either treated with water or with dilute acid. As 
the salts in the maize kernel are largely those soluble 
in water, the gluten meals and feeds, which are the 
residues, have a very small proportion of ash, not over 
half that in the original kernel. Analyses show that 
the potash is practically all extracted, and that the 
phosphoric acid is materially diminished. 

The mineral compounds of animal bodies. — The min- 
eral compounds of animals are nearly similar in kind to 
those of plants, but are very different in relative pro- 
portions. This is made plain by a comparison of the 
figures given below: 

Ash in plants and animals (per cent) 

Pot- Mag- Phos. Sul. 

Dry substance Total ash Soda Lime nesia acid acid 

Timothy hay . . 6.8 2.4 .12 .55 .22 .80 .19 

Maize kernel . . 1.4 .43 .02 .03 .22 .66 .01 

Wheat kernel . . 2.0 .61 .04 .06 .24 .93 .01 
Fresh bodies 

Fat ox 3.9 .14 .12 " 1.74 .05 1.56 

Fat sheep 2.9 .14 .13 1.19 .04 1.13 

Fat swine 1.8 .10 .07 .77 .03 .73 

Potash is much less prominent in the composition 
of the animal than is the case with plants, and phos- 
phoric acid and lime are much more so. In general, 
more than 80 per cent of the ash of the animal body 
consists of phosphoric acid and lime in combina- 
tion as calcium phosphate, whereas these two com- 
pounds constitute less than one-fifth of the ash of 



Silicic 
acid 


Chlor 
ine 


2.2 
.03 
.04 


.35 
.01 


.01 
.02 





Ash in Animal Bodies 49 

hay and less than one-half of the ash of maize and 
wheat kernels. 

The distribution of inorganic compounds in the animal 
body. — The bones contain a very large proportion of 
the ash constituents found in the animal body, the soft 
parts being poor in mineral salts. Usually the ash 
makes up between 60 and 70 per cent of bone, and the 
bony framework is from 6 to 9 per cent of the entire 
bodies of domestic animals. More than 80 per cent 
of the ash of bone is calcium phosphate, which is asso- 
ciated with calcium carbonate, calcium fluoride, calcium 
chloride and magnesium phosphate. 

The bones of all species of animals show a remark- 
able similarity of composition, the average of which 
would not be far from the following: 

In 100 parts of the ash of bone {average) 

Calcium phosphate 83. 9 

Calcium carbonate 13. 

Calcium in other combinations 35 

Fluorine 23 

Chlorine 18 

97.66 

The muscular tissue and other soft parts of the animal 
body contain less than 1 per cent of incombustible 
bodies. The ash of flesh is mostly phosphoric acid and 
potash, accompanied by comparatively small amounts 
of soda, lime and magnesia and minute quantities of 
chlorine and iron. Unquestionably, potassium phos- 
phate is the predominating salt in flesh, as calcium 
phosphate is in bone. 

D 



50 The Feeding of Animals 

The blood contains a variety of mineral substances, 
the chief of which is sodium chloride, or common 
salt, although a minute amount of iron is present, 
having a most important function. In the bile, soda 
is abundant, combined mostly with the peculiar or- 
ganic acids of this secretion. Chlorine is a constant 
constituent of the gastric juice, its presence as chlor- 
hydric acid being essential to digestion. The preceding 
are some of the prominent facts concerning the inor- 
ganic compounds of the animal body, but they are only 
a brief suggestion of the knowledge which pertains to 
this part of animal chemistry. 



CHAPTER V 

THE COMPOUNDS OF ANIMAL NUTRITION, CONTINUED 
— THE NITROGEN COMPOUNDS 

The nitrogen compounds of the vegetable and ani- 
mal kingdoms have received much attention from scien- 
tific investigators and writers during the past fifty 
years. It is quite the custom to declare that certain 
members of this class of substances are the ones most 
important in the domain of animal nutrition, and many 
writers give to protein so prominent a place in dis- 
cussing the relative value of feeding stuffs as to 
almost ignore the other nutrients. Certain investi- 
gators claim, on the other hand, that from the stand- 
point of results in practice the function and relative 
value of protein have been unduly magnified. What- 
ever may be the correct view concerning these antago- 
nistic opinions, it is very evident that the present 
tendency is towards a fuller discussion of the office 
and value of the non- nitrogenous bodies. 

There can scarcely be any disagreement, however, 
concerning the general proposition that protein plays 
a leading part in the processes and economy of animal 
nutrition. This is true for several reasons: 

(1) The nitrogen compounds are those fundamental 
to the energies of the living cells which make up the tis- 

(51) 



52 The Feeding of Animals 

sues of plants and animals. The basic substance of the 
active cell is protoplasm, a complex nitrogenous body, 
which Huxley called "the physical basis of life." Around 
this primal substance seem to center all vital activities, 
especially the transformation of the raw materials of the 
inorganic world into the organized structures of life. 

(2) These compounds are structurally essential to 
the growth of living tissues and to the formation of 
milk. The significance of this fact is intensified by 
their paucity in many of the feeding stuffs that are 
ordinarily produced on the farm . 

(3) Nitrogen combinations suitable for use as plant 
and animal food have reached a position of great com- 
mercial importance. They are the most costly of all 
the plant -building materials, the significance of which 
is intensified by their scarcity in the soil in useful 
forms, and by their easy passage beyond reach either 
through chemical changes which liberate the nitrogen, 
or through leaching from the soil. Nitrogenous feed- 
ing stuffs also bear relatively high market prices. 

PROTEIN 

For the sake of brevity and convenience, the nitro- 
gen compounds of cattle foods, both vegetable and 
animal, are designated as a class by the single term 
protein. When, therefore, it is stated that a feeding 
stuff contains a certain percentage of protein, refer- 
ence is made to the total mass of nitrogen compounds 
present, which may be many in number and of greatly 
differing characteristics. 



Protein 53 

It should be stated, by way of preliminary explana- 
tion, that, in the past, the proportion of protein (total 
nitrogen compounds) in a feeding stuff has been ascer- 
tained by determining the total amount of nitrogen 
and then multiplying its percentage number by the 
factor 6.25. This method is based on the assumption 
that the average percentage of nitrogen in protein com- 
pounds is sixteen, which is not true to so close a de- 
gree of approximation as was formerly believed to be 
the case. It may happen in some instances that a 
determination made in this way is sufficiently accurate, 
while in other cases the margin of error is large. Re- 
cent investigations with perfected methods show per- 
centages of nitrogen in the numerous single proteid 
substances found in the grains ranging from 15.25 to 
18.78. These are largest in certain oil seeds and lu- 
pines and smallest in some of the winter grains. Ritt- 
hausen, a prominent German authority, concedes that 
the factor 6.25 should be discarded, and suggests the 
use of 5.7 for the majority of cereal grains and legu- 
minous seeds, 5.5 for the oil and lupine seeds, and 6.00 
for barley, maize, buckwheat, soja bean, and white 
bean (Phaseolus), rape, and other brassicas. Nothing 
short of inability to secure greater accuracy justifies 
the longer continuance of a method of calculation 
which is apparently so greatly erroneous. 

As previously stated, protein is the accepted name 
for a class of compounds. Just how there came about 
such a grouping of a large number of substances under 
a single head it is not necessary to consider in this con- 
nection, but it should be made clear that the individual 



54 The Feeding of Animals 

compounds which are included under this term are in 
part so unlike in chemical and physical properties as to 
warrant the assertion that they have nothing in com- 
mon except that they contain nitrogen; and we may 
believe that their unlikeness in composition is do 
greater than the differences in their nutritive fuuctions. 

It is very evident that it is not only convenient, but 
necessary, to classify such a heterogeneous group of bod- 
ies into subdivisions more nearly alike in their charac- 
teristics. When we come to consider doing this we 
discover a most unfortunate confusion of terms. Our 
leading chemists evidently have reached no agreement 
in this matter, and so we find almost as many ways of 
dividing the nitrogenous compounds of plant and ani- 
mal life as there are prominent writers. 

Nevertheless, some system of classification must be 
used in this connection, and perhaps none is more con- 
venient or logical than the one reported by a commit- 
tee on nomenclature, representing the Association of 
Agricultural Colleges and Experiment Stations. 

The classification given here is essentially this one, 
although there are included in it certain distinctions 
very clearly set forth by Professor Atwater in a paper 
associated with the above-mentioned report. 

In the arrangement adopted it is recognized that 
certain nitrogen bodies included under protein are so 
unlike the main and important members of this group 
as to be properly st}'led non-proteid. It is also con- 
ceded that there are simple or native proteids which 
seem to stand in the relation of "mother" substances 
to a large number of protein bodies that have been 



Protein — Proteids 



55 



modified either by various external agencies, or are the 
result of a union of proteids with compounds of another 
class. More than all, the classification here used seems 
to be fairly well adapted to the effort of making clear 
to the beginner or unscientific reader this most difficult 
division of our subject. No apology is offered for the 
hard names that are used. They are the only ones 
available, and as they have the merit of conciseness, it 
is hoped that in time they will come into an intelligent 
popular use. These are: 

/Albumins 
Globulins 

Albuminoids 



Protein. To- 
tal nitrogen 
compounds . 



' Proteids 



(_ and allies 



Modified , 



f Derived 
\ Compound 



- Non-proteids 



Collagens or 
gelatinoids 

Extractives 

Amides, 

a m i d o , 

acids, etc. 



Other nitrogen compounds are included with the 
protein by the present methods of estimation, such as 
alkaloids and nitrates, but these are so uncommon in 
feeding stuffs, or are present in such small quantities, 
that they may be safely ignored. 

PROTEIN — THE PROTEIDS 



Proteids are the main and important nitrogen com- 
pounds either in the plant or in the animal. The pro- 
tein of seeds contains little else than proteids, while 
that of young fodder plants and especially of roots 



56 The Feeding of Animals 

consists more largely of non-proteids. They are also 
the chief constituents of muscular tissue. The chemical 
constitution of the proteids is not definitely known. 
No investigator has yet been wise enough to search out 
their manner of combination, but it is generally con- 
sidered to be very complex. It is believed that a cer- 
tain one of these compounds holds in a single molecule 
no less than 5,000 atoms. These bodies are con- 
structed from the simpler ones of the inorganic world 
through the vital energies of plants, and they appar- 
ently must come to the animal fully organized. 

The ultimate composition of proteids, that is, the 
proportions of the elements which they contain, has 
been carefully studied, and while there are material 
differences among them in this respect, the limits of 
variation are not especially wide, as can be seen from 
the following figures taken from Neumeister: 

Elementary composition of the proteids 

Per cent Per cent Average 

Carbon 50. to 55. 52. 

Hydrogen 6.5 to 7.3 7. 

Nitrogen 15. to 17.6 16. 

Oxygen 19. to 24. 23. 

Sulphur 3 to 2.4 2. 

We see that the number of elements ordinarily found 
in the proteids is five, nitrogen and sulphur being 
those that chiefly distinguish these bodies from all 
others which make up the mass of combustible matter. 
Two other elements are occasionally involved, as, for 
instance, the phosphorus of casein and the iron of 
blood. 



Protein — Albuminoids 57 

These proteids are familiar objects on the farm, and 
their properties are matters of common observation. 
.When the farmer's boy secures the tenacious cud of 
gum from the fresh wheat gluten, or when the house- 
wife watches the strings of coagulated albumin sepa- 
rate from the cold water extract of fresh lean beef that 
is brought to the boiling point, or observes the white 
of an egg harden into a tough, white mass as it is 
dropped into boiling water ; when we observe the 
stiffening of the muscular tissue of the slaughtered 
animal or the rapid formation of strings of fibrin in 
the cooling blood; — in all these instances there are 
manifested certain chemical or physical properties which 
pertain to these most important and useful com- 
pounds. 

The albuminoids. — Of all the nitrogen compounds, 
these exercise the most general and prominent func- 
tions in plant and animal life. They not only make up 
a large part of the protein of feeding stuffs, but their 
office in the nutrition of animals is definitely under- 
stood to be of the most important kind. 

As has been indicated, the albuminoids are regarded 
as divisible into groups, the individuals of each group 
having certain distinguishing common properties. The 
two subdivisions whose members are most common 
and widely distributed are the albumins and globulins. 
Among these and their derivatives and compounds we 
find albumin, myosin, fibrinogen, albuminates, pro- 
teoses, peptones, casein and nuclein, — a formidable lot 
of names whose use seems necessary to a statement of 
the facts we wish to discuss. It is hoped that the 



58 The Feeding of Animals 

following explanations will clothe them with practical 
meaning. 

(1) The albumins. There are several albumins. 
They are found in the juice of plants, in certain liquids 
of the animal body such as the serous fluids, in muscle, 
blood and milk, and abundantly in eggs. Unlike other 
proteids, these compounds are soluble in pure cold 
water, and when such a solution is heated to the boil- 
ing point, they separate from the liquid by coagulation 
and become insoluble unless acted upon by some strong 
chemical. 

When macerated beef is treated with cold water 
the albumin in it goes into solution, and if this ex- 
tract is boiled to make beef tea, it is a matter of com- 
mon observation that the albumin separates in clotted 
masses. None remains in the tea. It is w T ell for the 
housewife to know that all lean meat contains this 
substance, which by prolonged treatment with cold water 
may be removed to the detriment of the residue, and 
which, if the exterior surface of the meat is brought 
in contact with boiling water at once, coagulates in the 
outer laj-ers of the meat and thus prevents an exten- 
sive loss of soluble matter. 

The clear serous fluid which is left after removing 
the clot from blood contains albumin which may also be 
coagulated by heat. After the casein is removed from 
milk by acid or rennet, the albumin of the milk remains 
in the whey. It is this which in part causes milk to 
clot if brought to the boiling point. One of the most 
familiar examples of this class of proteids is the white 
of an egg, which, when cooking in boiling water, be- 



Protein — A Tbuminoids 59 

comes a hard, white, coagulated mass. Albumin in 
the serous fluids and in blood is called serum -albumin, 
in milk, lact- albumin and in eggs, ova-albumin. 

A small proportion of the proteids of plants is 
found to be albumin; for instance, Osborne found .6 
per cent in wheat, .43 per cent in rye, .3 per cent in 
barley, .5 per cent in soja beans, and some in most 
seeds. This possesses essentially the same characters 
as the animal albumin described previously. Whenever 
a vegetable substance is leached with water, it is prob- 
ably this proteid which would be the first to suffer 
removal or destructive fermentation. 

(2) The globulins. It is fully recognized that when 
plant and animal tissues are treated with water but a 
small part of the proteids dissolve. If, however, we 
add to the water a mineral salt, especially common salt 
(sodium chloride), sufficient to secure a 10 per cent 
solution, an additional and considerable amount of al- 
buminoids is extracted. These compounds are called 
globulins and differ from the albumins in being insolu- 
ble in pure water and in a saturated solution of certain 
mineral salts, such as sodium chloride. The globulins 
form an important part of the proteid content of plants 
and of animal tissues, both in quantity and in having 
a maximum nutritive usefulness. 

In plants these proteids seem to be especially abun- 
dant and widespread. Our best and most recent knowl- 
edge on this point comes from investigations conducted 
in the laboratory of the Connecticut Agricultural Ex- 
periment Station, chiefly by Osborne. In these re- 
searches the seeds of fifteen species of agricultural 



60 The Feeding of Animals 

plants were studied, all of which were found to contain 
globulins. In some the proteids consisted largely of 
these compounds. The percentage content in certain 
seeds was determined approximately: 

Globulins in certain seeds 

Per cent Per cent 

Kidney bean 20. Maize 0.4 

Cottonseed meal 15.8 Lentil 13. 

Peas. 10. Horse bean 17. 

Lupin 26.2 Soy bean Chiefly globulin 

The seeds of the legumes, as a rule, have the largest 
proportion of these albuminoids. 

From present knowledge, many seeds appear to have 
characteristic globulins which are unlike in their chem- 
ical properties. These have been given names derived 
from the general names of the species in which they 
are found. Thus we have amandin in almonds, ave- 
nalin in oats, corylin in walnuts, phaseolin in several 
species of beans, glycin in the soy bean, maysin in 
maize, vicilin in horse beans, vignin in the cow-pea, 
hordein in barley, and tuberin in the potato. One 
globulin called edestin appears to be quite generally 
distributed in the seeds of agricultural plants, having: 
been found in a larger number than any other proteid 
yet discovered, including all the cereals, castor bean, 
cottonseed, flaxseed, hemp, squash and sunflower, 
though it is not abundant in any one of these. 

The animal globulins of which we have definite 
knowledge are those that exist in the muscle and in 
the blood. The names which some of them bear are 
myosin, fibrinogen, paraglobulin, and, according to 



Protein — Albuminoids 61 

some authors, vitellin. If finely divided, well- washed 
muscle (lean meat) is treated with a 10 per cent salt 
solution, first by rubbing it in a mortar with fine salt, 
and then adding enough water to secure the proper 
strength of solution, a globulin is dissolved to which 
the name myosin has been given. The view has been 
generally accepted that this compound does not exist 
as such in living muscle, but forms there by coagula- 
tion upon the death of the animal. This change has 
been looked upon as similar to the coagulation of blood 
through the formation of fibrin, and is regarded as the 
explanation of the stiffening of dead muscles (rigor 
mortis). The theory is held that a "mother" substance 
exists in the living muscle from which myosin is formed 
in much the same way as fibrin is developed in clotting 
blood from a preexisting body, but no single view as to 
exactly what occurs is fully accepted. There is, never- 
theless, a general agreement that rigor mortis is due 
to a clotting of the muscle, accompanied by marked 
chemical transformations, one final product being my- 
osin. The theory is advanced that ferments are present 
in the muscle, to the influence of which these changes 
are due, and without which they do not occur, but 
proof of this view is still lacking. In this whole field 
much is yet to be learned. Certainly, the chemistry of 
living and dead muscle is most profound, and offers to 
the bio-chemist a wonderfully attractive and fruitful 
field of research. 

Another prominent and remarkable globulin is the 
fibrinogen, which is found in the blood. It is common 
knowledge that when blood is drawn from the veins 



62 The Feeding of Animals 

and cools it clots, a phenomenon which is nothing more 
than the formation of strings of fibrin. Fibrin as such 
is not found in living blood, but is one of the prod- 
ucts into which fibrinogen splits when exposed blood 
cools, probably because of the influence of a ferment. 
Stranger than all is the fact that so long as the blood 
is retained in the arteries and veins, even if the animal 
dies and grows cold, this clotting does not appear. 

Serum globulin is a collective name for several glob- 
ulins, which exist in blood serum and in the other fluids 
of the animal body, such as lymph and its allies, in- 
cluding those exudations which pertain to diseased 
conditions, especially dropsical. 

One more proteid has been generally classified as a 
globulin, although differing in some respects from the 
other members of this class. Reference is made to 
vitellin, which is the principal proteid in- the yolk of 
eggs. It is there intimately mixed with certain pecu- 
liar phosphorized bodies, which we shall notice later. 

The modified albuminoids. — All of the proteids pre- 
viously noticed may properly be called simple, native 
proteids. This characterization is appropriate because 
these are the bodies that possess the typical reactions 
and qualities of the albuminoids as a class, and are the 
principal ones found in the normal tissues of plants 
and animals. They are the basal substances from 
which others appear to be derived after modifications 
of one kind or another. It seems proper, therefore, to 
speak of certain other proteids as modified albuminoids, 
because, through various influences, either natural or 
artificial, they have acquired chemical and physical 



Protein — Modified Albuminoids 63 

properties unlike those possessed by the mother sub- 
stances. 

A convenient division of these modified bodies, 
though perhaps not strictly scientific, may be made 
in accordance with the cause or manner of change. 
These causes are: (1) coagulating ferments; (2) heat; 
(3) aetion of acids and alkalies; (4) the ferments of 
digestion; (5) combinations with other compounds. 

(1) Coagulating ferments. Reference has been 
made to that interesting phenomenon, the coagula- 
tion or clotting of blood. As stated, this is now 
known to be due to a formation of a new compound, 
called fibrin. The mother substance, fibrinogen, and 
not the fibrin exists in the living blood, and it 
seems to be well proven that the splitting of the fibrin- 
ogen into two substances, one of which is fibrin, is 
due to the action of a ferment, designated as a fibrin 
ferment. It would be out of place to review the data 
upon which this conclusion is based. There are, to 
be sure, conflicting views, but the one stated seems to 
be the most fully established. Fibrin, after thorough 
washing, is an elastic white substance, which, in its 
chemical properties, stands very close to the albumins 
that are coagulated by heat. 

It has been held by various investigators that other 
changes in animal fluids and tissues are brought about 
in the same manner as the formation of fibrin, i. e., by 
the action of a ferment. In one case, this is certainly 
true, viz.; the curdling of milk under the influence of 
the ferment rennin. This ferment, which for cheese- 
making purposes is extracted from the fourth stomach 



64 The Feeding of Animals 

of a calf, will, when added to milk at a proper tem- 
perature, cause the coagulation which gives us the 
cheese curd. The probable correct explanation of this 
familiar phenomenon is that the casein is decomposed 
into two other substances, one being paracasein and 
the other an albumin, the first of which subsequently 
unites with lime salts in the milk and forms the in- 
soluble substance that we know as curd. The occur- 
rence of this latter step appears to be proven by the 
fact that in the absence of lime salts no curd forms, 
but it immediately appears when such salts are added 
to the lime -free solution. As milk always contains 
sufficient lime to make coagulation possible, this ex- 
planation of the coagulation of casein has chiefly a 
scientific interest. 

Mention has been made of the clotting of dead 
muscle, or rigor mortis. As stated, certain investi- 
gators have suggested that the formation of the muscle 
clot is a process analogous to the coagulation of blood, 
and is brought about by ferment action. This view 
is not yet proven and must at present be considered as 
only hypothetical. If, however, it is found to be cor- 
rect, myosin would properly be classed as a derived 
albuminoid, its progenitor being the native proteid. 

(2) Heat. The effect of a boiling temperature 
upon the albumins has already been described. They 
are coagulated into a mass no longer soluble in water 
and only redissolved by treatment which changes their 
chemical constitution. The same thing happens to 
nearly all the globulins, and as with the albumins, 
this begins at varying temperatures. These coagu- 



Protein — Modified Albuminoids 65 

lated bodies, which are typified by the white of an egg 
after contact with boiling water, are materially unlike 
the original compounds, though the nature of the modi- 
fication is not understood. We know them simply as 
coagulated albumins and globulins. 

(3) Action of acids and alkalies. When albumins 
and globulins are treated with dilute mineral acid, such 
as hydrochloric, they dissolve, through their .conversion, 
into acid albuminates. The action of dilute alkalies is 
similar, only that alkali -albuminates are formed. An- 
other effect of dilute acids upon proteids is to cause 
them to take up water, or suffer hydrolysis. These 
hydrolyzed bodies are called proteoses as a general 
name. This term signifies that they are derived from 
proteids. More fully specialized names are albumose, 
from albumin; globulose, from globulin; caseose, from 
casein, and so on. The important property which the 
proteoses takes on is their greater solubility as com- 
pared with the original compounds. This change has 
an intimate relation to digestive processes, or to the 
transference of the insoluble albuminoids of the food 
into the blood circulation, because in the stomach the 
hydrochloric acid of the gastric juice plays somewhat 
the same part as in dilute artificial solutions in render- 
ing the proteids soluble. 

(4) Ferments of digestion. When we come to a 
discussion of the processes of digestion we shall learn 
that nearly every digestive fluid contains one or more 
ferments, whose office appears to be to cause certain 
necessary modifications of the food proteids. The gen- 
eral effect of these ferments is to induce these proteids 

E 



66 The Feeding of Animals 

to take up water, which transforms them to proteoses, 
and finally to peptones, the latter being so soluble as 
to pass through the walls of the alimentary canal into 
the blood. These proteoses are similar to those formed 
by the action of dilute acids, and in digestion may 
be considered as products intermediary between the 
original food proteids and the peptones which are the 
final result of albuminoid digestion. The acid of the 
stomach and the alkaline compounds in certain intesti- 
nal juices cooperate -in bringing about these necessary 
changes, for we know that in their absence the digestive 
ferments have no extensive action such as that de- 
scribed. Proteoses, i. e., albumoses, globuloses, case- 
oses, and the like, are soluble in water, are not coagu- 
lated by boiling their solutions, and in other ways are 
unlike the proteids from which they are derived. They 
are regarded, however, as not having lost their albu- 
minoid character, and, as will be shown later, they are 
re-formed by the metabolic energy of the animal into 
bodies similar to those from which they take their rise*. 

(5) Combinations. There are many nitrogenous 
compounds found in plants and animals which it is 
not possible to classify at present in any exact manner. 
They are undoubtedly derived from simple proteids, as 
those to which reference is made consist of albuminoids 
united to a body of a different kind. 

There are, first of all, certain bodies designated as 
nucleo- albumins, this name signifying that albumin is 
united to a nuclein, which, in its turn, is a combination 
of an albumin with phosphoric acid. The best known 
nucleo -albumin in agriculture is the casein of milk. 



Protein — Modified Albuminoids 67 

Some of the properties of this body have been noticed 
in discussing the action of ferments. It has others 
which it is well to mention. In the first place, casein 
is not soluble in water. It is not in solution as it ex- 
ists in milk, but is regarded as being in a swollen con- 
dition. Again, it does not coagulate when milk is 
boiled. While the skin which forms on the surface 
of milk at a boiling temperature contains casein as 
one component, the only genuine coagulation that oc- 
curs is of the albumin present. Every housewife has 
noticed that when vinegar is added to milk in a small 
quantity the milk curdles. This is because the casein 
is modified by a weakly acid medium. A generous 
quantity of common salt, or of certain other salts, 
would have a similar effect. 

The nuclein, which forms a part of casein, can be 
split into an albumin and phosphoric acid, and is an 
illustration of a class of compounds which are gen- 
erally distributed in plant and animal tissue. The name 
is suggestive of the fact that these bodies exist in the 
nuclei of living cells, having an intimate relation to the 
protoplasm. Nucleins are also found in milk and eggs, 
and it appears quite possible that they take a pecu- 
liarly important place in nutrition, especially with 
young animals and milch cows. 

Another compound widely distributed in the animal 
kingdom is mucin, a prominent constituent of the 
slimy secretions of the mucous membranes that line 
the passages of the animal body, such as the throat 
and the intestines. This substance appears somewhat 
anomalous in being a combination of a proteid and a 



68 The Feeding of Animals 

carbohydrate (animal gum). The fact of such a union 
is demonstrated by boiling mucin with an acid when 
an acid albuminate and carbohydrate -like body are 
produced. The mucin-like bodies are not especially 
important in nutrition. 

The blood contains a modified proteid which has an 
importance second to none in its relation to the nu- 
tritive processes. Reference is made to haemoglobin, 
which arises from the union of an albumin called 
globin and a coloring matter (pigment) called haema- 
tin. The latter is peculiar in containing iron. The 
especial function of haemoglobin is as a carrier of oxy- 
gen, and it is enabled to do its work through the 
property of taking in and releasing oxygen with great 
readiness. This action will be discussed later when 
we consider respiration. 

The gelatinoids. — It is a matter of common obser- 
vation in cookery that when meat containing tendons 
(cartilage) or bones is submitted to the action of 
boiling water there is obtained in the extract a sub- 
stance, which, especially when it is cold, we recognize 
as the one known as gelatine. Gelatine as such is not 
found in the animal tissues, but is derived from certain 
constituents of the connective tissues like the collagen 
of tendons and of bones, that from the latter source 
being also known as ossein. Collagen is undoubt- 
edly transformed into gelatine by taking up water. 

Gelatine is insoluble in cold water, but dissolves 
in hot. As the dry commercial article, it is a tena- 
cious substance which, when prepared in thin layers, 
is transparent. When collagen is acted upon by tan- 



Protein — Non - Proteids 69 

nic acid, as for instance, when the skin of an animal 
is treated with an extract of hemlock or oak bark, the 
result is a substance which does not putrefy, and which 
gives to a tanned hide the properties of leather. 

Keratin and similar substances . — The hair, wool, 
hoofs, horns, and feathers are made up chiefly of 
a compound which bears the name keratin. Chemi- 
cally, it is closely related to the true proteids, we may 
believe, because when treated with heat or with chemi- 
cals like acids and alkalies, the resulting products are 
nearly similar to those that are secured in the same 
ways from albumins. Sulphur is a much more promi- 
nent constituent of keratin than of the native pro- 
teids, the analyses of human hair showing as high as 
5 per cent, the average amount found in horn being 
3.30 per cent. These keratin bodies belong usually to 
the epidermis or outer skin of the animal, and are 
modifications of the exterior tissue to serve certain 
distinct purposes where rigidity or wearing quality is 
necessary. 

PROTEIN — THE NON - PROTEIDS 

There are certain nitrogen compounds included in 
the term protein which are non-proteid in character, 
that is, they possess physical and chemical properties 
greatly removed from those which characterize albumin 
and other true proteids. Their office as nutrients is 
also less comprehensive than that of the albuminoids. 

One group of non -proteids which we speak of under 
the general term amides, is found chiefly in plants. 



70 The Feeding of Animals 

They are soluble in water, and consequently are diffu- 
sible throughout the plant tissues. It is believed that 
they are the forms in which the nitrogen compounds 
of the plant are transferred from one part to another, 
as, for instance, from the stem to the seed. It has 
generally been held that amides are more abundant in 
young plants than in mature. A larger part of the 
nitrogen of roots and tubers is found in these com- 
pounds than in other feeding stuffs, the proportion in 
grains being the least, and is very small indeed. Such 
investigations as have been conducted point to the 
conclusion that amides are not muscle -formers, as is 
the case with proteids. This is a reason for regarding 
the protein of coarse foods, roots, and tubers, as of 
less value than that of the grains and grain products. 

The extractives are bodies found in the extract ob- 
tained from beef with cold water. After the albumin 
has been removed from such an extract by boiling, 
these compounds known as creatin and creatinin chiefly 
constitute the nitrogenous solids that remain. Their 
food value is small if anything, for they appear to 
pass through the body without change. 



CHAPTER VI 

THE COMPOUNDS OF ANIMAL NUTRITION, CONCLUDED — 
THE NITROGEN- FREE COMPOUNDS 

Much the larger proportion of dry cattle foods 
consists of non- nitrogenous material. This is espe- 
cially true of hays and cereal grains, consequently we 
find that from 75 to 80 per cent of the dry matter 
stored in a farmer's haymows and grain -bins is made 
up of substances of this class. While these com- 
pounds are not regarded by many as fundamentally so 
important as the nitrogenous, in quantity they un- 
questionably occupy the first rank. The activities of 
plant life are largely devoted to their production, and 
their use by animal life is correspondingly extensive. 
They may properly be called the main fuel supply of 
the animal world. Other nutrients aid in maintaining 
muscular force and animal heat, to be sure, but these 
compounds are the principal storehouse of that sun- 
derived energy which furnishes the motive power ex- 
hibited in all animal life. They are also important 
building materials, for they fill a necessary office of 
this kind in the formation of milk and in the growth 
and fattening of animals. 

The compounds of this class contain only three ele- 
ments, — carbon, hydrogen and oxygen. They may 

(71) 



72 The Feeding of Animals 

be derived, therefore, wholly from air and water, and 
they constitute that portion of our cattle foods which 
is drawn from never -failing and costless sources of 
supply. 

The elementary composition of typical nitrogen - 
free bodies is given in this connection: 

Cellulose Starch Glucose Saccharose Stearin Olean 

<fc $ $ "k <fr $> 

Carbon 44.4 44.4 40. 42.1 76.7 77.4 

Hydrogen.. 6.2 6.2 6.7 6.4 12.4 11.8 

Oxygen 49.4 49.4 53.3 51.5 11. 10.8 

The non- nitrogenous compounds of feeding stuffs 
are usually divided into three main classes, viz.; crude 
fiber, nitrogen -free extract and fats or oils. The sec- 
ond class is sometimes spoken of as carbohydrates, 
because it includes the carbohydrates as its principal 
members, and the third is known by the chemist as 
ether -extract, because ether is used to extract the fats 
or oils from the vegetable substances in which they are 
contained. The actual fat obtained from hay and 
other feeding stuffs is always less, however, than the 
ether -extract. 

CRUDE FIBER 

This is the tough or woody portion of plants. It 
consists largely of cellulose, a familiar example of 
which in a nearly pure form is the cotton fiber used 
in making cloth. Crude fiber is separated from asso- 
ciated compounds by the successive treatment of vege- 
table substance with weak acids and alkalies, and as so 
determined is sometimes improperly taken to represent 



Crude Fiber in the Plant 73 

the amount of cellulose in a plant. While crude fiber 
is mainly cellulose, it contains a small proportion of 
other compounds, and besides, more or less cellulose 
is dissolved by the acid and alkali treatment, so that 
the percentages of crude fiber given in fodder tables 
only approximately measure the cellulose present in 
feeding stuffs. 

All plant tissue is made up of cells, the walls of 
which are chiefly or wholly cellulose. It is this sub- 
stance out of which is built the framework of the plant, 
and which gives toughness and rigidity to certain of 
its parts. The more of this a feeding stuff contains, 
the more tenacious it is, other things being equal, 
and the more difficult of mastication. 

The proportion of crude fiber in plants varies greatly 
with the species. Large plants have more than small 
ones, as a rule. The dry matter in the trunks and 
limbs of trees is mostly woody fiber, and the chemical 
treatment involved in making paper from wood has for 
its main object the separation of this from other sub- 
stances. Grass and other small herbage plants are less 
rich in fiber, still less existing in such species as pota- 
toes, turnips and beets. 

The proportions of cellulose in the different parts of 
a plant are greatly unlike. It is usually most abundant 
in the stem, with less in the foliage and least in the 
fruit. With vegetables like potatoes and turnips, the 
leaves are much richer in fiber than the tubers or roots, 
which contain a comparatively small proportion. Of the 
grains or seeds considerable is present in the outer coat- 
ings, while but little is found in the interior. Cousid- 



74 The Feeding of Animals 

ering feeding stuffs as a whole, we find that hays, and 
especially straws, are rich in crude fiber, while tubers, 
roots and the grains contain only small amounts. In 
certain by-product grain foods, like bran, which is made 
up mostly of the seed -coatings, fiber is present in fairly 
large proportions, while in other materials like gluten 
meal, which are derived from the inner parts of the 
grain, the percentages are very small. 

The stage of growth at which a plant is used for 
fodder purposes has a marked influence upon the pro- 
portion of crude fiber. In young, actively growing vege- 
table tissue, the cell -walls are thin, but as the plant in- 
creases in age, these thicken, chiefly through the depo- 
sition of cellulose. Pasture grass has less cellulose than 
hay, and early cut grass less than that which is ripe. 
In general, the toughness and hardness of mature plants, 
as compared with young, is due to the increased pro- 
portion of woody fiber, although the decrease in the 
relative amount of water in the tissues and the deposi- 
tion of other substances have more or less effect. 

NITROGEN -FREE EXTRACT 

This name, like protein, is a collective term, being 
used to designate a group of compounds possessing 
certain characteristics in common. A great variety of 
substances are included under this head, many of which 
are among the most familiar objects of every -day life. 
Here we find the starches, sugars, gums and vegetable 
acids, compounds universally used, and which even chil- 
dren recognize by name. Certain of these non-nitrog- 



Nitrogen -free Extract — Carbohydrates 75 

enous bodies of less importance are not so well known, 
as, for instance, such uncommon sugars as mannose 
and galactose, and their mother substances, mannan 
and galactan. 

The manufacture of beers and liquors and many of 
the ordinary phenomena of cooking operations, are based 
upon the chemical properties of the starches and sugars. 
To the presence of these and related bodies is due many 
of the agreeable flavors and appetizing characteristics of 
certain foods, as, for instance, the sweetness or acidity 
of fruits, and flavors produced in grain foods under the 
influence of heat. 

The most prominent and important members of the 
nitrogen -free extract group are known as carbohy- 
drates, the significance of this term being that these 
compounds contain carbon united with hydrogen and 
oxygen in the proportions in which these two elements 
exist in water. 

A common and convenient classification of the car- 
bohydrates, though not strictly rational from the stand- 
point of chemical constitution, is the following: 1. The 
starches, such as corn and potato starch and those 
bodies similar in elementary composition, including cel- 
lulose, inulin, glycogen, the dextrins, pectin and the 
gums. 2. The sugars, of which there are two main 
classes, the glucoses and the sucroses, the main sugar 
of "corn syrup" being a familiar example of the former 
class, and the ordinary crystallized sugar of commerce 
the most prominent member of the latter. 

The starches. — Starch is a widely distributed and 
abundant constituent of vegetable tissue. Food plants, 



76 The Feeding of Animals 

especially those most used by the human family, con- 
tain it in generous proportions, in some seeds as much 
as 60 or 70 per cent being present. Probably only water 
and cellulose are more abundant in the vegetable world. 

Starch does not exist in solution in the sap, but is 
found in the interior of plant cells in the form of 
minute grains, which have a shape, size and structure 
characteristic of the seed in which they are found. 
Potato starch grains are large, about Tihr of an iuch 
in diameter, and are kidney- shaped, while those of the 
wheat are smaller, about ToVo of an inch in diameter, 
and resemble in outline a thick burning-glass. Corn- 
starch grains are angular, being somewhat six-sided, 
and those of other seeds show marked and specific 
characteristics. These differences in size and shape 
furnish the most important means of detecting adul- 
terations of one ground grain with another, as, for 
instance, when corn flour is mixed with wheat flour, a 
practice not unknown at the present time. 

Unless modified by some chemical change, starch is 
not dissolved by water. The starch grams are not 
affected by cold water, and in hot water at first only 
swell and burst. Prolonged treatment with hot water 
causes chemical changes to more soluble substances. 
For this reason the simple leaching of a fodder mate- 
rial removes no starch; at least not until fermentation 
occurs. At the same time the treatment of a ground 
grain with hot water so breaks up the starch grains 
that they are probably acted upon more promptly by 
ferments and digestive fluids, though perhaps no more 
fully, than when not treated. 



Nitrogen -free Extract — Starches 77 

It is somewhat customary to refer in a popular way 
to the nitrogen -free extract of feeding stuffs as synony- 
mous with starch and sugar. Such a comparison con- 
veys an erroneous impression. The nitrogen - free 
extracts of many feeding stuffs, notably the straws 
and hays, contain at best a very small proportion of 
these carbohydrates, the amount of starch often being 
inappreciable. It is doubtful whether these coarse 
fodders usually contain enough to be chemically de- 
termined. This has certainly been found to be true 
in some cases. On the other hand, the dry matter of 
many seeds, such as rice and the cereal .grains, wheat, 
maize, barley or oats, is largely made up of starch. 
The same is true of potatoes and other tubers. John- 
son quotes the following figures from Dragendorff: 

Amount of starch in plants 

Per cent Per cent 

Wheat kernel.'. 68.5 Peas 39.2 

Rye kernel 67. Beans 39.6 

Oat kernel 52.9 Flaxseed 28.4 

Barley kernel 65. Potato tubers 62.5 

It appears that in grain plants starch forms most 
abundantly during the later development of the seed. 
At the Maine station none could be found in very im- 
mature field corn cut August 15, while on September 
21 the dry matter of the whole plant on which the ker- 
nels had matured to the hardening stage contained 
15.4 per cent. In general, the stem and leaves of for- 
age plants are poor in starch. 

The distribution of starch in seeds is worthy of 
note. The grain of wheat has been carefully studied 



78 The Feeding of Animals 

in this particular, and it is found that this body does 
not normally exist in the seed -coatings, this tissue con- 
sisting largely of mineral matters, proteids, cellulose, 
and gums. On the contrary, the germ and the interior 
material deposited around it are rich in starch. To be 
sure, wheat bran, which is now very largely the outer 
seed -coats of the grain, has more or less, but this is 
due to imperfect milling. It is very evident, there- 
fore, that the term nitrogen -free extract, as applied 
to different cattle foods, stands for greatly unlike mix- 
tures of compounds, for we have largely starch in the 
cereal grains and mostly other substances in the straws 
and other coarse fodders. The importance of this fact 
will appear in considering the digestion and value of 
food compounds. 

Starch is an important commercial article, and for 
this purpose is mainly obtained from corn' and pota- 
toes. It is used as human food, as a source of dextrin 
and in other ways. By treatment with an acid, corn- 
starch is converted into the glucose of our markets. 

The vegetable gums. — It has become evident, doubt- 
less, during our discussion of nitrogen -free extract, 
that a considerable portion of this class of compounds 
consists of something else than the carbohydrates al- 
ready noticed. For example, at the Maine Experiment 
Station, the composition of several samples of corn 
fodder was closely investigated. It was found that 
the proportions of starch and sugar varied greatly, 
mostly in accordance with the stage of growth, being 
much more abundant in the mature plant. Even 
with flint corn nearly ripe, not over one -half of the 



Nitrogen- free Extract — Vegetable Gums 79 

nitrogen -free extract of the entire plant was found to 
be starch and sugars. The other half evidently con- 
sisted of bodies either not so well known or not known 
at all. 

Among the less familiar compounds which we now 
recognize as existing quite abundantly in the stem and 
leaves of many, if not all, fodder plants are the vege- 
table gums, some of which are designated by the 
chemist as pentosans. Only a few such substances 
are definitely known, one of which, araban, is con- 
tained in gum arabic, gum tragacanth, cherry gum, 
beet pulp, and doubtless in various other materials; 
another being zylan or wood gum, which may be sep- 
arated in abundance from wood and straw. Stone has 
examined a large number of agricultural products for 
these gums, and if present methods of analysis are 
accurate, he found in the dry matter of such feeding 
stuffs as hays from several species of grass, corn fod- 
der, sugar beets, rutabagas, wheat -bran and middlings 
and gluten meal from 6 to over 16 per cent, the high- 
est proportions appearing in timothy hay, corn fod- 
der, and wheat -bran. In mature field -corn fodder 
he obtained about 16 per cent, thus accounting for 
about half of the nitrogen -free extract left after sub- 
tracting the starch and sugars. Wheat bran contained 
much more than middlings, and the least was present 
in gluten meal. These gums are surely much more 
abundant in the coarse foods than in the grains, a 
fact which, as we shall learn, is important in com- 
paring the nutritive value of different classes of feed- 
ing stuffs. 



80 The Feeding of Animals 

The pectin bodies. — Another class of compounds 
much like the gums, and perhaps related to them 
chemically, is the pectin bodies. Some of these sub- 
stances are gelatinous in appearance. The jellying of 
fruits, such as apples and currants, is made possible by 
4;heir presence. They exist in greater abundance in 
unripe fruit than in the ripe, consequently the former 
is selected for jelly-making. When such fruits are 
cooked, the pectin which they contain takes up water 
chemically and is transformed into a gelatinous sub- 
stance, and the secret of jelly-making is in stopping 
the cooking process before the chemical transforma- 
tions have passed beyond a certain point. Mucilages 
not greatly unlike the gums and pectins exist in cer- 
tain seeds and roots, the most notable instance being 
flaxseed. 

The sugars. — When considered from the stand- 
point of efficiency, the sugars are the most valuable 
of all the carbohydrates, although in quantity they are 
much less important than the starches, because they 
are found only in small amounts in the hays and to a 
scarcely appreciable extent in the ^grains. Certain dis- 
tinctively sugar plants, to be mentioned later, are 
^wd agriculturally, which are sometimes used as 
cattle foods. 

Unlike starch, the sugars are found in solution in 
the sap of growing plants. It is probable that these 
are the forms in which carbohydrate material is trans- 
ferred from one part of the plant to another. It is 
easy to see that some such medium of exchange is 
necessary. The actual production of new vegetable 



Nitrogen- free Extract — Sugars 81 

substance takes place in the leaves. When, therefore, 
cell -walls and starch -grains are to be constructed, in 
the stem and fruit, the building material must be car- 
ried from the leaves to these parts in forms which will 
readily pass through intervening membranes. Except- 
ing certain soluble compounds, closely related to starch, 
the sugars appear to be the only available bodies fitted 
for this office. 

It is very seldom that a plant contains only a single 
sugar. Generally two or more sugars are found to- 
gether. This is especially the case in the corn plant, 
sorghum and the juicy fruits, and the proportions of 
each depend somewhat upon the stage of growth of 
the plant. 

The most important sugar, commercially considered, 
is saccharose, which is the ordinary crystallized product 
of the markets. As a human food it is widely used, and 
is especially valuable ; and its manufacture and sale con- 
stitute a prominent industry. This sugar is obtained 
mostly from two plants, sugar cane and the sugar beet. 
It also exists abundantly in sorghum and in considerable 
proportions in ordifkfy field corn. The first spring flow 
of sap in one species of maple tree is richly charged 
with it, and in a few states large quantities of maple 
syrup and sugar are manufactured. 

Saccharose is not a prominent constituent of the 
more common cattle foods. While it occurs in meadow 
grasses, in sweet potatoes and in roots, and perhaps in 
minute proportions in certain seeds, it is onl3 r when the 
fresh corn plant, sorghum and sugar beets are fed that 
it constitutes a material part of the ration. In corn 



82 The Feeding of Animals 

stover and in silage there is practically none, it having 
been destroyed by the fermentations that have taken 
place. 

The fruits generally contain saccharose, mixed with 
other sugars and organic acids, and upon the relative 
proportions of these compounds depends the character 
of the fruit as to acidity or sweetness. 

A sugar that is intimately related to the first growth 
which occurs in the germination of seeds is maltose, 
for it stands as an intermediate product between the 
store of starch in the seed and the new tissues of the 
sprout. The solution that the brewer extracts from 
the malted grains contains this compound as the prin- 
cipal ingredient, and through succeeding fermentations 
in the beer vats it is broken up into alcohol and other 
compounds. It sustains an important relation, there- 
fore, to the production of beers and other alcoholic 
liquors. The glucose syrups found in the markets some- 
times contain small quantities of this sugar. It is also 
found abundantly in the intestinal canal during the di- 
gestion of food, being derived from starch and other car- 
bohydrates. Maltose is similar to cane sugar in ultimate 
composition but not in constitution, though as a nutrient 
it evidently has an equivalent value. So far as known, 
however, it does not appear to occur in material quan- 
tities in feeding stuffs. 

Another important sugar is dextrose or grape sugar, 
or what is known in the markets as glucose. Excepting 
in the hands of the chemist it is seldom seen as crystals, 
although these appear in the "candying" of honey and 
of raisins. Its commercial forms are molasses and the 



Nitrogen -free Extract — Acids 83 

syrups. Dextrose is found in practically the same plants 
that contain saccharose, such as sorghum, maize and the 
fruits. So far as known, it is always associated with 
some other sugar. On account of its difficult crystalli- 
zation and a lower degree of sweetness, it is less valuable 
for commercial purposes than cane sugar. That which 
appears in the market is largely made from starch by the 
use of an acid, and it is often utilized in adulterating 
the more costly saccharose. Many seem to regard glu- 
cose as a substance deleterious to health, but in consid- 
eration of the fact that in digestion, starch and most 
other sugars are reduced to this compound before en- 
tering the circulation of the animal, this view does not 
seem to be sustained. In fact, there is a lack of evi- 
dence to show the ill effect of glucose either upon man 
or animals. 

Still another sugar is levulose or fruit sugar, the 
composition of which is identical with dextrose but w r hich 
has a different chemical constitution. It accompanies 
dextrose and is found in some fruits in considerable 
quantities. It is as sweet as cane sugar, but does not 
form crystals with the same readiness. 

The acids. — Other substances besides those of a car- 
bohydrate character are included in the nitrogen -free 
extract. Chief among these are the organic acids, com- 
pounds which are found mostly in the fruits, although 
they appear in certain fermented products, such as silage 
and sour milk. The most important and well-known of 
these are acetic acid, found in silage and vinegar, citric 
acid in lemons, lactic acid in sour milk and silage, malic 
acid in many fruits, such as currants and apples, and 



84 The Feeding of Animals , 

oxalic acid in rhubarb. Sometimes these acids are free, 
that is, not combined with any other compound, and 
sometimes they are united with lime or some other base, 
forming a salt. Excepting the fruits, only fermented 
feeding stuffs contain acids to an appreciable extent. 
When milk sours, the sugar in it is changed to lactic acid 
under the influence of a ferment. In silage, various 
acids develop, the main one being lactic, accompanied 
by acetic and other acids in much smaller proportions. 
These are formed chiefly at the expense of the sugars 
that enter the silo in the corn or other material which 
is subjected to fermentation. 

ANIMAL CARBOHYDRATES 

A study of the composition of the animal body 
teaches us that, unlike plants, it is very poor in carbo- 
hydrate compounds. Only two carbohydrates are of 
distinctively animal origin, viz; glycogen or animal 
starch, and milk sugar. 

Glycogen is closely related to starch, having the same 
percentage composition. It is a white powder, soluble 
in water, and may be extracted in very small amounts 
from the muscles and liver, the latter being the place 
where it is produced. As we shall see later, it seems to 
perform a very important office in nourishing the animal 
body. It was formerly believed that another carbohy- 
drate exists in muscle called inosite, but it is now known 
that this substance belongs to a different class of com- 
pounds. 

The only sugar of animal origin which is abundant 



Nitrogen- free Extract — Carbohydrates 85 

in farm life is that found in milk and which is known 
in commerce as milk sugar or lactose. The milk of all 
mammals contains sugar, which appears to be the same 
compound with every species so far investigated. When 
fed wholly from the mother, this is the only carbohydrate 
which young mammals receive in their food. The aver- 
age proportion of sugar in the milk of domestic animals 
varies from three to six parts in a hundred, cow's milk 
containing about five parts. When the cream is removed 
much the larger part of sugar remains in the skimmed 
milk, and in cheese- making it is nearly all found in the 
whey, from which the milk sugar of commerce is ob- 
tained. Very soon after milk is drawn, unless it is 
heated to the point of sterilization, or is treated with 
some antiseptic, the lactose begins to diminish in quan- 
tity, being converted into lactic acid through the action 
of germ life. Sour milk, therefore, is different from 
sweet in at least one compound, and this change causes 
at least a slight modification of food value. 

CHEMICAL RELATIONS AND CHARACTERISTICS OF 
THE CARBOHYDRATES 

The various carbohydrates, which have been pre- 
viously described, are greatly unlike in appearance, 
taste and other physical qualities, but they are closely 
related chemically. This is shown not only by what 
the chemist knows of their constitution, but also by 
the readiness with which one passes into another, 
for example, the transformation of starch into dex- 
trose. Under the influence of certain agencies, such as 



86 The Feeding of Animals 

heat, ferments and hot acids, certain carbohydrates may 
be changed to other bodies of the same class. This 
fact is important in the arts, and no less so in plant 
and animal nutrition. The movements of these com- 
pounds in plants and their uses as nutrients depend 
largely upon these transformations, as do also certain 
phenomena in cookery. 

Heat is one immediate cause of some of these 
changes. Starch, when heated, becomes dextrine, a 
water-soluble, gum -like substance. This occurs in 
baking corn and wheat bread; so it does in toasting 
bread, and the bread -crust tea of the sickroom is in 
part a solution of dextrine. Probably this substance 
is digested with greater ease than starch, because it is 
an intermediate stage between starch and glucose, the 
latter being the final product. 

Hot, dilute acids, even the vegetable acids, such as 
those found in vinegar and in fruits, transform starch, 
dextrin, gums and pectin bodies into various sugars, of 
which dextrose is the principal one. Saccharose is 
changed to dextrose and levulose in the same way. 
These chemical facts find an application in the manu- 
facture of glucose from cheaper materials, and in cook- 
ery where vinegar and acid fruits are used. 

These transformations are also brought about by 
the influence of bodies called ferments. For instance, 
the carbohydrates in a grain of barley are largely not 
available for nourishing the new growth that takes 
place during germination, because, being mostly insolu- 
ble, they cannot be transferred from the seed to the 
point where new tissue is formed. It is so arranged 



Nitrogen -free Extract — Carbohydrates 87 

that a ferment present in the seed, called diastase, 
acts upon the starch and converts it into maltose, a 
sugar. The brewer takes advantage of this fact when 
he malts or germinates barley, this being nothing more 
than the same change of starch into sugar, which oc- 
curs during germination in the ground. This maltose 
is utilized by the young plant to form new tissue and 
by the brewer as a source of alcohol. In the animal 
body, especially in the mouth and intestines, are found 
ferments which accomplish essentially the same result. 
Through their diastatic influence the starch, dextrose, 
cane sugar and other carbohydrates are transformed, 
probably by successive stages, finally into glucose (dex- 
trose mainly) in which form the carbohydrate nutri- 
ents enter the blood. 

The chemical changes so far noted are all in one 
direction, i. e., the taking up of the elements of water 
to form new compounds, as, for instance, the trans- 
formation of starch to dextrose or cane sugar into in- 
vert sugar. 

Up to the present time, however, no chemist has 
discovered a way of reversing this process, and by ab- 
stracting the elements of water from the glucoses pro- 
ducing cellulose, starch and cane sugar. That the plant 
can do this, however, is certainly true. Cell walls and 
starch grains are undoubtedly made from the sugars 
under the influence of what we blindly call vital force. 

The carbohydrates, especially the sugars, possess 
such chemical properties as cause them to be easily de- 
stroyed and lost from the feeding stuff in which they 
are contained. If grass or corn fodder is allowed to lie 



88 The Feeding of Animals 

in a mass in a green or wet condition, there is very 
material loss of dry matter, dne to the breaking up of 
the sugars aud other carbohydrates into new compounds 
under the influence of ferments. This action occurs in 
the silo, where the sugars are used to form considerable 
quantities of acids besides water and carbon dioxid. 
Loss from this cause often occurs in the grain bin, 
where new grain not sufficiently dry is stored. The 
sugars in canned vegetables or fruits that are not prop- 
erly heated or sealed soon disappear, either to be lost 
in gasecus products or to be converted into compounds 
of an entirely different character. All such fermenta- 
tions result in a diminished food value. Not only is 
there an actual disappearance of dry matter from the 
affected material, but this is brought about at the ex- 
pense of some of the most valuable food compounds. 
For this reason the farmer should exercise great care 
in the storage and preservation of his cattle foods. The 
dangers of loss from these fermentations are greater 
than is generally appreciated, for the cheinist finds that 
in drying green or wet foods under conditions more 
favorable than often pertain to farm practice he is un- 
able to avoid it to a greater or less extent. 

FATS OR OILS 

When any finely -ground feeding stuff, either straw 
or hay, is submitted to the leaching action of ether, 
chloroform, or certain other liquids, several compounds 
are taken into solution, the main and important ones 
being fats or oils. These bodies make up the chief 



Fats or Oils 89 

portion of such an extract from seeds, while material 
so derived from hay, straw and other coarse fodders 
also contains a considerable amount of wax, chlorophyll 
and other substances. Tables that show the compo- 
sition of feeding stuffs have a column which is some- 
times designated "ether -extract," and sometimes "fats 
or oils." The former is the more accurate term, be- 
cause the compounds which it is the intention to de- 
scribe are often no more than half fats or oils. The 
real value of the "ether -extract " from different feed- 
ing stuffs is partly determined, therefore, by its source. 
When it is all oil, or nearly so, it is worth much more 
for use by the animal than when it is made up to quite 
an extent of other bodies. 

The proportions of fat or oil in feeding stuffs vary 
within wide limits. In general, seeds and their by- 
products contain more than the coarse foods, the differ- 
ences in the percentages of actual oil being greater 
than is indicated by the ether -extract. Straws natu- 
rally have less oil than the hays. But little is found 
in the dry matter of roots and tubers. Among the 
cereal grains and other more common farm seeds, corn 
and oats show the largest amounts, the proportion in 
dry matter being from five to six in one hundred, while 
wheat, barley, rye, peas, and rice contain much smaller 
percentages, wheat having about 2 per cent, and rice 
sometimes not over one -fifth of 1 per cent. Agri- 
cultural seeds that are especially oleaginous are cotton- 
seed, flaxseed, sunflower seeds, and the seeds of many 
species belonging to the mustard family, such as rape. 
Peanuts, cocoanuts and palm nuts are also very rich in 



90 The Feeding of Animals 

oil. The average percentages in these seeds and nuts 
are approximately as given below: 

Oil in certain seeds 

Per cent Per cent 

Linseed 34 Peanuts 46 

Cottonseed 30 Cocoanuts 07 

Sunflower seed 32 Palm nuts 49 

Rape seed 42 Poppy seed 41 

Mustard seed 32 

The oils from all the above are important commer- 
cial products, being used in a great variety of ways 
in human foods and in the arts. In many cases, the 
refuse from this extraction goes back to the farm as 
food for the cattle. This is especially true of linseed 
and cottonseed. 

The vegetable and animal fats and oils may, for 
convenience' sake, be discussed in two divisions, the 
neutral fats or glycerides and the fatty acids. The neutral 
fats are combinations of the fatty acids with glycerine. 
When, for instance, lard is treated at a high tempera- 
ture with the alkalies, potash and soda, glycerine is 
set free and an alkali takes its place in a union with 
the fatty acids. This is the chemical change which 
occurs in soap -making. There are several of these neu- 
tral fats, the ones most prominent and important in 
agriculture being those abundant in butter and in the 
body fats of animals; viz., butyrin, caproin, caprylin, 
caprin, laurin, myristin, olein, palmatin, and stearin. 
Butyrin is a combination of butyric acid and glycer- 
ine, stearin of stearic acid and glycerine, and so on. 

These individual fats possess greatly unlike physical 



Fats or Oils 91 

properties. At the ordinary temperature of a room 
some are liquid and some are solid, olein belonging to 
the former class and palmatin and stearin to the latter. 
It is a matter of common observation that butter, lard 
and tallow differ in hardness at a given temperature, 
and by the use of a thermometer it may easily be dis- 
covered that their melting points are not the same. As 
these animal fats are in all cases chiefly mixtures of 
olein, palmatin, and stearin, stearin being a solid at 
ordinary temperatures, and olein a liquid at anything 
above the freezing point, it is evident that the relative 
proportions of these compounds will affect the ease of 
melting and the hardness of the mixtures of which they 
are a part. Tallow having more stearin than lard and 
butter aud less olein, is consequently much more solid 
on a hot day. 

Milk fat contains not only the three principal fats 
but also the others mentioned, butyrin, caproin, caprylin, 
caprin, laurin and myristin, in small proportions, and 
these latter tend to give butter certain properties that 
distinguish it from the other animal fats, which are 
almost wholly palmatin, olein and stearin. Doubtless 
the flavor, texture and resistance of butter to the effects 
of heat are much influenced by the proportions of the 
numerous fats it contains, but there is much connected 
with this subject of which we are still ignorant. 

Free, fatty acids exist in nature. They are not found 
in butter, lard and tallow unless these substances have 
undergone fermentations, or, as we say, have become 
rancid. The characteristic flavor of strong butter is due 
to free butyric acid, which, because of fermentations, 



92 The Feeding of Animals 

has parted from the glycerine with which it was origi- 
nally combined in the milk. In plant oils, on the other 
hand, are found considerable proportions of the free 
fatty acids, some of which have not been discovered so 
far in animal fats, either free or uncombined. 

Perhaps no one has studied plant oils more thor- 
oughly than Stellwaag, who investigated the ingredients 
of the ether and benzine extracts from plants. His 
results show that not only do these extracts include 
substances which are not fats, but that a considerable 
proportion of free fatty acids is always present, some- 
times in quantities exceeding the neutral fats: 

Composition of ether -extracts {per cent) 

Neutral Free fatty Material not 
fats acids saponifiable 

Hay 23.7 37.3 30.8 

Malt sprouts 24.7 30.1 34.5 

Potatoes 16.3 56.9 10.9 

Beets 23. 35.3 10.7 

Maize, kernel 88.7 6.7 3.7 

Barley. 73. 14. 6.1 

Oats 61.6 27.6 2.4 

It appears, as before stated, that ether -extract, es- 
pecially that from coarse fodders, may consist, to a large 
extent, of materials which should not be classed among 
the fats. Stellwaag demonstrated that only about 60 
per cent of the hay extract which he investigated con- 
sisted of oil. On the contrary, the extracts from- the 
grains proved to be nearly all oil. Moreover, the grain 
oils were made up principally of glycerides, and those 
from hay, malt sprouts, potatoes and beets consisted 
largely of free fatty acids. 



CHAPTER VII 

THE COMPOSITION OF THE BODIES OF FARM ANIMALS 

The principal compounds existing in the bodies of 
our farm animals have been quite fully considered on 
preceding pages. It now remains for us to learn some- 
thing of the proportions of these substances that are 
needed in constructing the carcasses and other tissues 
of steers, sheep and swine; for it is about these spe- 
cies that we have the most extensive and accurate 
knowledge as related to chemical composition. Cer- 
tainly such knowledge is important. The animal is 
the direct product of food, and before we can consider 
intelligently the functions of food nutrients and the 
ways in which they are made to fulfil their offices, we 
must understand what is to be done. So far, then, as 
it is a matter of construction, what must be accom- 
plished by the use of food in building the bodj r of an 
animal ? It has doubtless become evident from fore- 
going statements that many compounds are common 
to the vegetable and the animal kingdoms. The chem- 
ical constituents in plants and animals are classified in 
the same way, also; viz., water, ash, or mineral com- 
pounds, protein, carbohydrates, and fats. Here the 
similarity stops, for the proportions of these classes 
as found in the fat steer and in the stalk of maize are 

(93) 



94 The Feeding of Animals 

entirely unlike, and what is true in this respect of the 
steer and the maize is true of all other animals and 
plants. The dry matter of the vegetable world con- 
sists most largely of fiber, starch and other carbohy- 
drates, while animal tissues contain these compounds 
in so small a proportion as to be inappreciable in stat- 
ing the percentage composition. In the average animal 
dry matter, as it appears in the market, the fats are 
the leading constituents, and the proportion of protein 
is more than twice, perhaps three times, that in average 
vegetable tissue. 

In considering the composition of farm animals, 
we may first divide the body substances into water and 
dry matter. The dry matter, aside from the contents 
of the stomach and intestines, and the food ingredients 
in the way to being used, essentially belongs to three 
classes of compounds, ash, protein, and fats, which, as 
is the case with water, are present in greatly varying 
proportions in different species, and even in the same 
species according as the animal is young or old, lean or 
fat. Our knowledge on this subject is largely derived 
from the investigations of Lawes and Gilbert, at Roth- 
amsted, England. These investigators carried through 
the great effort of analyzing the entire bodies of ten 
animals representing two species at different ages, and 
three species in different conditions of fatness. At the 
Maine Experiment Station in this country, the bodies 
of four steers were analyzed, exclusive of the skin, two 
steers being younger and not so fat as the other two. 
From these data a very fair knowledge may be obtained 
not only of the composition of the bodies of bovines 



Composition of Farm Animals 95 

» 

sheep, and swine, but also of the extent to which this 
composition is affected by age and condition : 

Composition of farm animals (per cent) 

Species Water Ash Protein Fat 

Ox, well-fed 66.2 5.9 19.2 8.7 

Ox, half-fat 59. 5.2 18.3 17.5 

Ox, fat 49.5 4.4 15.6 30.5 

Sheep, lean 67.5 4. 18.3 10.2 

Sheep, well-fed 63.2 3.9 17.4 15.5 

Sheep, half-fat 58.9 3.8 16. 21.3 

Sheep, fat 50.9 3.3 13.9 31.9 

Sheep, very fat 43.3 3.1 12.2 41.4 

Swine, well-fed 57.9 2.9 15. 24.2 

Swine, fat 43.9 1.9 11.9 42.3 

Fat calf 64.6 4.8 16.5 14.1 

Steer, 17 -months 59.4 4.4 17.4 18.8 

Steer, 17-months 57.1 5.2 17.5 20.2 

Steer, 24-months 53.1 5.1 16.6 25.2 

Steer, 24-months 53.4 5.2 16.8 24.6 

It is always more or less surprising" to the learner 
to ascertain that the bodies of farm animals of vari- 
ous species and in various conditions are about half 
water. This is water that is not in any way chemically 
united with associated compounds, but exists in the 
blood and tissues in a free state, and may be dried out 
in the usual manner. Next to water, fat is the most 
abundant material, protein and ash following in the 
order named. 

Perhaps the most striking fact displayed is the great 
variation in the proportion of these ingredients accord- 
ing to the age and condition of the animal. For in- 
stance, the percentage of water in the fat calf is much 



96 The Feeding of Animals 

greater than in the fat ox, and this is an illustration 
of a general truth, that mature animals are less watery 
than young ones. The amount of water present in the 
animal body is also influenced to a marked extent by 
the degree of fatness. The half -fat ox contained over 
8 per cent more water than the fat, the store sheep 22 
per cent more than the extra fat, and the store pig 14 
per cent more than the fat. The explanation of this, 
as before stated, is not that fat replaces water already 
in the tissues of the lean animal, but that the increase 
is much more largely dry matter than was the original 
body substance. It is obviously true, also, that in fat- 
tening an ox or sheep, thus increasing the relative 
amount of fat, the proportions in the dry substance of 
ash and protein are decreased. The above statements 
are explained by the results obtained by Lawes and 
Gilbert in determining the composition of the increase 
while animals are fattening: 

Water Ash Protein Fat 

i i $ % 

Lean ox 66.2 5.9 19.2 8.7 

Lean sheep 67.5 4. 18.3 10.2 

Well-fed swine 57 9 2.9 15. 24.2 

Average of lean animals .. . 63.9 4.3 17.5 14.3 
Av. of increase while fattening 23.8 1.1 7.3 67.8 

This comparison of the composition of lean animals 
and of the increase when they are fattened is a sufficient 
explanation of the less watery and fatter condition of 
the animal when ready for the market. The store 
animal is nearly two -thirds water and about one -sev- 
enth fat, while the increase is less than one -quarter 



Composition of Farm Animals 97 

water and over two -thirds fat. The percentage of pro- 
tein in the increase is also very small. 

Not only does fattening an animal materially modify 
the composition, but the proportion of butcher 7 s meat 
is greatly increased- 

Proportion of dressed carcass (per cent) 

Ox Sheep Swine 

Lean animal 47. 45. 73. 

Fat animal 60. 53. 82. 

These slaughter tests were made by Lawes and Gilbert, 
and they explain in part why a fat steer is worth so 
much more per pound of live weight, even if the quality 
of the meat is no higher. It may be said, in a gen- 
eral way, that the carcass portion of the animal body 
varies with bovines and sheep from 50 to 65 per cent 
of the live weight, according to age and condition. 
SwiDe "dress away" not far from one -fifth. 

It would be possible to go further in our discussion 
of the animal body and consider it from the structural 
or anatomical point of view. It is certainly important 
to know something of the organs involved in digestion, 
respiration and assimilation if we would reach a clear 
understanding of how the food is made available and 
utilized, but such facts as are deemed necessary con- 
cerning these specialized tissues we will take up in 
their appropriate connections. 



G 



CHAPTER VIII 

THE DIGESTION OF FOOD 

We have accepted so far without discussion the 
almost self-evident fact that the food is the immediate 
source of the energy and substance of the animal body. 
It now remains for us to consider the way in which the 
nutrition of an animal is accomplished. The first step 
in this direction is the digestion of food. It is necessary 
for food ingredients to be placed in such relations to the 
animal organism that they are available for use. This 
involves both condition and location. The various 
nutrients in the exercise of their several functions must 
be generally distributed in all the interior parts of the 
animal. It is obvious that hay and grain as such cannot 
be so distributed, and so their compounds must, in part 
at least, be brought into a soluble and diffusible condi- 
tion, in order that they may pass through the mem- 
branous lining which separates the blood-vessels and 
other vascular bodies from the cavity of the alimentary 
canal. 

In discussing physiological relations of food, two 
terms are employed: viz., digestion and assimilation. 
Digestion refers to the preparation of food compounds 
for use, by rendering them soluble and diffusible, 
changes which are accomplished in what we call the ali- 
os) 



Digestion — Ferments 99 

mentary canal, a passage that begins with the mouth, 
includes the stomach and intestines, and ends with the 
anus. Assimilation signifies the appropriation of nu- 
trients, after digestion, to the maintenance of energy 
and to the building of flesh and bones, processes taking 
place in the tissues, to which the nutritive substances 
are conveyed by the blood. The two terms are entirely 
distinct in meaning, although they are confused in popu- 
lar speech. 

In digestion, a feeding stuff undergoes both mechani- 
cal and chemical changes. It is masticated, that is, 
ground into finer particles, after which, in its passage 
along the alimentary canal, it comes in contact with 
several juices which profoundly modify it chemically. 
That portion of it which is rendered diffusible is ab- 
sorbed by certain vessels that are imbedded in the walls 
of the stomach and intestines, and is conveyed into the 
blood. The insoluble part passes on and is rejected by 
the animal as worthless material, and constitutes the 
solid excrement or feces. A study of digestion includes, 
then, a knowledge of mastication, of the sources, nature 
and functions of the several digestive juices, and a con- 
sideration of the various conditions affecting the extent 
and rapidity of digestive action. 

FERMENTS 

The changes involved in rendering food compounds 
soluble are intimately connected with a class of bodies 
known as ferments, to which brief reference has already 
been made in their relations to the preservation of feed- 

LofC. 



100 The Feeding of Animals 

ing stuffs; and it seems necessary before proceeding to 
a consideration of digestion as a process to learn some- 
thing of the nature and functions of these agents, which 
are actively and essentially present in the digestive tract. 

A ferment may be denned in a general way as some- 
thing which causes fermentation; in other words, the 
decomposition of certain vegetable or animal compounds 
with which it comes in contact under favorable condi- 
tions. Ferments are of two kinds, organized and unor- 
ganized. Organized ferments are low, microscopic forms 
of vegetable life, generally single -celled plants. Unor- 
ganized ferments are not living organisms, but are sim- 
ply chemical compounds. 

When milk is allowed to remain in a warm room for 
several hours it becomes sour. An examination of it 
chemically shows that its sugar has largely or wholly 
disappeared and has been replaced by an acid. A study 
of the milk with the microscope, before and after sour- 
ing, reveals the fact that there has been a marvelous in- 
crease in it of single-celled organisms or plants. The 
growth of this form of life is "regarded as the cause of 
the change of the sugar into lactic acid. We have here 
the so-called lactic -acid ferment, which may typify the 
organized ferments known as bacteria. Numerous other 
fermentations of the same general kind are common to 
every- day experience. The changes in the cider barrel 
and the wine cask, the spoiling of canned fruits and 
vegetables, and the heating of hay and grain are illus- 
trations of what is accomplished by these minute organ- 
isms. Bacteria that cause disease, and which multiply 
in the organs and other tissues of the animal body, may 



Digestion — Ferments 101 

also be properly called ferments, because in their growth 
new compounds are formed which are as truly fermenta- 
tive by-products as the carbonic acid and alcohol of cider 
and beer making. As this subject viewed on its patho- 
genic side is not important to the feeder, we need to 
study organized ferments only so far as they relate to 
the preservation of feeding stuffs and to changes in the 
alimentary canal. We shall be best equipped for con- 
trolling ferments and preventing their destructive action 
if we know what they are, and understand the general 
conditions under which they thrive. We should also 
know how, and to what extent, their action occasions 
harm. 

The organized ferments are classed in the vegetable 
kingdom. As a rule, each individual plant is a single 
cell, varying in shape and so minute as to be invisible 
to the unaided sight. It corresponds in its general 
structure to the cells which make up the tissues of the 
higher vegetable species, i. e., it consists of a cell wall 
inside of which are protoplasm and other forms of 
living matter. These organisms are distributed every- 
where, — in the air, in the soil, on surfaces of plants 
and in the bodies of animals. Whenever the right 
opportunity offers itself, they are ready to begin to 
multiply and bring about all the results attendant 
upon their growth. 

The conditions essential to their development are 
the proper degree of moisture and temperature and 
the necessary food materials. Thoroughly dry animal 
and vegetable substances do not ferment. Hay and 
grain that have been dried to a water content of 10 



102 The Feeding of Animals 

per cent will keep a long time without loss from fer- 
mentative changes. The heat of a mow of new hay 
or of a bin of new grain, with its subsequent musty 
condition, is due to the fermentations that are made 
possible through the presence of considerable moisture. 
Thorough drying is a preventive of destructive fer- 
mentations. 

There is a temperature at which each vegetable fer- 
ment thrives best, and there are limits of temperature 
outside of which the growth of these forms of life does 
not occur, or is very slight. Numerous species thrive 
between 75° and 100° F. Fermentable materials like 
fruit and meat at the freezing point or below are not 
subject to fermentations. The boiling point of water 
kills most bacteria, and temperatures above 150° F. 
retard or entirely prevent their growth. 

Like all life, these organisms must have food. 
Many species find this in acceptable forms in vegetable 
products. Because they generally contain the sugar, 
albuminoids, and mineral compounds which nourish 
bacteria, feeding stuffs are always the prey of ferments 
under proper conditions of moisture and heat. The 
prevention of fermentation in cattle foods is desirable 
because it occasions a loss of nutritive value. This 
becomes evident when we consider the nature of the 
chemical changes that occur. For instance, when sugar 
is broken up through the influence of a bacterium, new 
compounds are formed which take up free oxygen. 
This means that combustion occurs, causing the lib- 
eration of energy which otherwise would have been 
available to the animal, if the sugar had been taken 



Digestion — Ferments 103 

as food. Many fermentations involve oxidation, all of 
which are destructive of food value. 

Several theories have been advanced to account for 
the action of the orgauized ferments. The most plausi- 
ble seems to be that these little plants use sugar 
and other compounds as food, deriving energy there- 
from, the carbonic acid, alcohol and other new bodies 
being the by-products of this use. Whatever may be 
the real explanation of the changes that occur, fer- 
mentations due to plant growth are among the most 
useful agencies with which the farmer deals, and may 
be the most harmful. 

There is another class of ferments which is termed 
unorganized, and to which the general name enzym is 
given. These are the ferments especially important in 
digestion. They are merely chemical compounds which 
produce a peculiar effect upon certain bodies with which 
they come in contact. If a thin piece of lean beef be 
suspended in an extract from the mucous lining of a 
pig's stomach, to which has been added a small pro- 
portion of hydrochloric acid, the liquid being kept at 
about 98° F., the beef will soon begin to soften, after- 
wards swell to a more or less jelly-like condition and 
finally dissolve. The same general result would occur 
with fish, blood fibrin or the coagulated white of an 
egg. When starch, which is not affected by pure, warm 
water, is placed in a warm water solution of crushed 
malt it soon dissolves, leaving a comparatively clear 
liquid. A chemical examination of these preparations 
will reveal the fact that the compounds of the meat 
are present in solution in somewhat modified forms, 



104 The Feeding of Animals 

and that the starch has been changed to a sugar or 
other soluble bodies. In both cases substances insolu- 
ble in water have become soluble and diffusible. 

The cause of these changes is the presence of typical 
bodies, one in the pig's stomach and one in the malt, 
ferments of the enzym class, the former of which ren- 
ders albuminoids soluble, the latter acting to produce 
a similar result with the insoluble carbohydrates. This 
action is different from that of the organized ferments, 
where oxidation occurs in many cases. The enzyms 
simply induce the albuminoids and starch to take up 
the elements of water, which apparently does not greatly 
diminish their energy value. How this is done cannot 
be explained in simple terms, if at all. Our knowledge 
of the manner of the change rests entirely upon theo- 
retical grounds. The digestion of food is almost wholly 
accomplished through the specific effect of enzjmi bod- 
ies, of which every digestive fluid contains one or 
more. Examples of these are the pepsin and pan- 
creatin of the drug store that contain enzyms mixed 
with more or less impurities. The function of each 
of these ferments we shall consider as we proceed to 
discuss the various steps of digestion. 

THE MOUTH 

The first step in the digestion of fodders and whole 
grains is to reduce them to a much finer condition. 
This is done in the mouth, the teeth being the grind- 
ing tools.* Sometimes the cutting or grinding is par- 

* This is not true of hens, turkeys and other fowls. 



Digestion — The Mouth 105 

tiall}* or wholly performed for the animal in hay-cutters 
and grain mills. However this may be accomplished, 
it is an essential operation for two reasons, (1) it puts 
the food in condition to be swallowed, and (2) fits it 
for the prompt and efficient action of the several diges- 
tive fluids. Dry whole hay or kernels of grain could 
hardly be forced down the tube leading to the animal's 
stomach. It is necessary for these materials to be" 
broken down and moistened in order that they may be 
swallowed. Even if they could be conveyed to the 
stomach in their natural condition the process of ren- 
dering their constituents soluble would proceed very 
slowly. Common experience teaches us how much 
more quickly finely powdered sugar or salt will dis- 
solve than the large crystals or lumps. The more 
finely any solid is ground, the larger is the surface ex- 
posed to the attack of the dissolving liquid, and this is 
as true of foods as of sugar or salt. 

Prompt and rapid solution of food is essential, be- 
cause if it is too long delayed, uncomfortable and in- 
jurious fermentations are likely to set in, and because 
of imperfect digestion, the final nutritive effect of the 
ration may be diminished. For these reasons, animals 
with diseased teeth, or those that have lost teeth, 
make poor use of their food, and require an unneces- 
sary amount to keep them in condition. These condi- 
tions may often be a cause, especially with horses, of 
disappointing results from an ordinarily sufficient ration. 

The teeth of our domestic animals differ somewhat 
in number and arrangement. Authorities state the 
following to be the usual number: 



106 The Feeding of Animals 

Total Incisors Canines Molars 

Horse 36-40 12 4 24 

Ox 32 8 24 

Sheep and goat 32 8 24 

Pig 44 12 4 28 

The incisors or front teeth are those which are used 
for prehension, and by grazing animals for cutting off 
the grass and other herbages. With the ox, sheep and 
goat, incisors are found only in the lower jaw. These 
shut against a tough pad on the upper jaw. They are 
constantly wearing off, and with old animals may be so 
worn away as to leave only the roots. Such animals 
do not graze successfully. With the horse and pig, in- 
cisors are found in equal numbers in both jaws. 

The molars are the grinding teeth. Those of the 
horse sometimes need filing on the outside edges in 
order to prevent irritation and soreness of the adjacent 
tissues. A diseased molar may occasion an animal 
much discomfort and cause imperfect mastication. 

During mastication there is poured into the mouth 
a liquid called the saliva, which has two important 
functions: (1) it moistens the food, and (2) with sev- 
eral species of animals it causes a chemical change in 
certain of the constituents of the food. 

The saliva has its origin in several secretory glands 
that are adjacent to the mouth cavity, and from these 
this liquid is poured into the mouth through ducts that 
open in the cheek under the tongue. The chief of 
these glands are located in the side of the face, below 
and somewhat back of the jaws and beneath the tongue, 
and are called the parotid, the submaxillary and the 



Digestion— The Mouth 107 

sublingual. Other glands of this character are scat- 
tered in the cheeks and at the base of the tongue. 
The anatomy and arrangement of these organs are not 
essential to our subject. We are chiefly interested in 
the liquid which they secrete. 

The saliva is a transparent and somewhat slimy 
liquid, and contains generally not less than 99 parts 
in 100 of water, and one part or less of solid matter. 
It is alkaline in reaction, because of the presence of 
compounds of the alkalies. The specific chemical effect 
exerted by this liquid on the food constituents may 
be illustrated by subjecting starch to its action. When 
this is done, the starch gradually disappears as such 
and is replaced by maltose, the same sugar that we 
find in barley malt. The chemist has learned that 
the agent which is active in causing this change is 
a ferment, to which the name ptyalin has been given, 
and which is always present in the saliva of man and 
of some animals. It is classed among the diastatic 
ferments, because it has an office similar to that of 
diastase in the germination of seeds; viz., the trans- 
formation of the starch into a sugar. This change 
begins in the mouth and probably continues in the 
stomach until the food becomes so acid that the fer- 
ment ceases to act, for ptyalin is inactive except in 
an alkaline medium. There is no reason for supposing 
that any considerable proportion of the starch of a 
ration is transformed by the saliva, but this solvent 
action which continues later in the digestive processes 
certainly begins in the mouth in the manner described. 

The saliva also moistens the food, which is a most 



108 The Feeding of Animals 

important office, for it is a necessary preparation to the 
act of swallowing. With large rnminants, the quantity 
of saliva required for this purpose is large, as is evident 
when we remember that an ox or cow may consume in 
one day 24 pounds of very dry hay and grain, and that 
rumination goes on much of the time while the animal 
is not eating. It is estimated that oxen and horses se- 
crete from 88 to 132 pounds daily, an apparently enor- 
mous quantity of liquid for secreting organs no larger 
than the salivary glands to supply. 

THE STOMACH 

When the food leaves the mouth, it passes down the 
gullet (oesophagus) into the stomach. The only modi- 
fications it has suffered up to this point are its reduction 
to a finer condition and a slight action of the mouth 
ferment upon the starch, an influence which doubtless 
continues in the stomach for a larger or shorter pe- 
riod, according to circumstances. After the food is 
swallowed changes of another kind begin sooner or 
later, affecting the protein compounds especially. 

Before considering gastric digestion from a chemi- 
cal point of view, we should become acquainted with 
the widely differing structure of the stomachs of the 
various farm animals. Those of the ox and horse are 
greatly unlike. The stomach of the ox, and of all other 
ruminants, consists of four divisions or sacs, whereas 
with the horse and pig it is made up of a single sac. 

The ruminant stomach is really quite a complicated 
affair, and the way in which it disposes of the food is 



Digestion — The Stomach 



109 



understood only after a careful study of details. Its 
four divisions or sacs are the paunch, honeycomb, 
many -plies and rennet, or what the physiologist has 
named the rumen, reticulum, omasum and abomasum. 
With the ox these cavities contain on the average not 
far from fifty -five gallons, about nine -tenths of this 
space belonging to the paunch. Fig. 1. 




Fig. 1. Stomach of ox. 

T, rumen or paunch, showing attachment of oesophagus. 

C, reticulum or honeycomb. 

O, omasum or many-plies. 

A, abomasum or rennet, showing attachment of small intestine. 

The food, in its descent from ,the mouth, passes at 
first mostly into the paunch through a slit in the gul- 
let. This cavity, as stated, is very large, and it may 
properly be considered as an immense reservoir for the 
storage of the bulky materials which the ruminants 
take as food. As is the case with the entire digestive 
canal, the walls of the paunch are composed of three 
layers of tissue, the middle one being a very thick 



110 The Feeding of Animals 

muscular coat, which seems necessary to produce the 
movement of large masses of food. The inner or 
mucous layer is covered with numerous leaflike pro- 
jections, in which the blood-vessels are freely distrib- 
uted. During its stay in this reservoir, the moist food 
becomes thoroughly softened and besides undergoes a 
variety of changes, chiefly those due to the organized 
ferments combined perhaps with the continued action 
of the saliva. These fermentations cause an almost 
constant evolution of gases, which are as constantly 
absorbed by the blood. It is suggested that the rapid 
puffing up of the paunch of a freshly -killed bovine is 
due to the failure of the blood to take up these gases. 
Sometimes unnatural and dangerous fermentations set 
in, induced often by the consumption in the spring of 
a large quantity of easily fermentable food such as 
green clover. This causes hoven, and unless the gas 
pressure is at once relieved by an opening into the 
paunch the animal dies, often after the bursting of the 
rumen. 

A portion of the food reaches the reticulum or 
honeycomb, either through the cesophagal slit when 
first swallowed, or through a large opening between 
the paunch and the honeycomb. The reticulum also 
communicates with the third stomach by an opening. 
This is the smallest division of the stomach, and de- 
rives its common name from the fact that its interior 
surface is divided by ridges of the mucous membrane 
into cells which bear a close resemblance to a honey- 
comb. These cells, which are several sided and quite 
deep, appear to be a "catch-all" for the foreign bodies 



Digestion — The Stomach 111 

which animals are liable to swallow, such as small 
stones, pins and nails. The contents of this compart- 
ment of the stomach are very watery, a condition which 
is said to aid the return of the food to the mouth, por- 
tion by portion, for remastication. 

Rumination, which is the re -chewing of food pre- 
viously swallowed, is peculiar to bovines, sheep and 
goats. In the case of these species, the mastication of 
coarse fodder is not completed before it is swallowed 
the first time, and they have the power of returning to 
the mouth the material which has become stored in the 
paunch and honeycomb in order that it may be more 
finely ground. This is what is termed "chewing the 
cud." It is an operation which greatly aids digestion 
in rendering the food mass finer and more susceptible 
to the action of the digestive fluids. Animals fed on 
grain alone do not ruminate. They "lose their cud," 
a condition popularly and erroneously supposed to be 
fatal to the animal's life. 

After remastication, the food does not return wholly 
to the first and second stomachs, but is mostly carried 
along in what is known as the oesophagal groove to the 
third stomach, the omasum. The finer portions may 
even do this when first swallowed. The many -plies 
(omasum) is a cavity somewhat larger than the honey- 
comb, which has a most curious interior structure. It 
is filled with extensions of the mucous membrane in 
the form of leaves, between which the food passes in 
thin sheets, an arrangement which seems to have for 
its purpose the further grinding of the food so that 
when it finally reaches the fourth and last compart- 



112 . The Feeding of Animals 

ment it is in a very finely -divided condition and is 
thoroughly prepared for the action of the juices that 
are subsequently poured upon it. 

It is at the last stage of the journey of the food 
through this complicated stomach that it is submitted 
to the true gastric digestion. As a matter of fact, the 
abomasum or rennet is regarded as the true stomach, 
the other three sacs being considered as enlargements of 
the oesophagus. In the calf, the rennet is the only part 
developed, the other divisions not coming into use 
until the animal takes coarse foods in considerable 
quantity. The fourth stomach is larger than either 
the second or third. It receives directly from the 
omasum the finely divided food, upon which it pours 
the gastric juice, a liquid that is secreted in large 
quantity by glands located in its inner or mucous 
membrane. This juice, like all the digestive fluids, 
is mostly water, the proportion being between 98 
and 99 parts to less than two parts of solids. The 
latter consist of ferments, a certain amount of free or 
uncombined hydrochloric acid and a variety of mineral 
compounds, prominent among which are calcium and 
magnesium phosphates and the chlorides of the alka- 
lies, common salt being especially abundant. 

Especial interest pertains to the ferments of the gas- 
tric juice, one of which, in connection with free hydro- 
chloric acid, causes a most important change in the 
proteids of the food by reducing albuminoids, such as 
the gliadin and glutenin of the wheat kernel to soluble 
forms. We know quite definitely about this action, 
because it can be very successfully produced in an ar- 



Digestion — The Stomach 113 

tificially prepared liquid. If the mucous lining of a 
pig's stomach, after carefully cleaning without washing 
with water, is warmed for some hours in a very dilute 
solution of hydrochloric acid, an extract is obtained 
which has the power of dissolving lean meat, wheat 
gluten and other proteid substances. The active agent 
in causing this solution is pepsin, an unorganized fer- 
ment or enzym which is present in the gastric fluid of 
all animals. It changes albuminoids to peptones, bod- 
ies so soluble and diffusible that they pass readily into 
certain small vessels which are distributed in the walls 
of the alimentary canal and thus become available as 
nutrients. The other ferment present in the gastric 
juice is the one which gives to rennet its value as a 
means of coagulating the casein of milk in cheese- 
making, and is called rennin. The action of this latter 
body is especially prominent in the stomach of the calf 
when fed exclusively on milk, and it is the calf's active 
stomach, the fourth in the mature animal, which is the 
source of commercial rennet. 

The free hydrochloric acid in the gastric juice is also 
actively concerned in proteid digestion. It is found 
that a solution of pepsin has little or no effect in the 
absence of free acid, for when, during artificial diges- 
tion, the supply of this acid is used up it must be 
renewed or digestion ceases. 

The stomach of the horse and pig consists of a 
single sac, so that digestion with these animals is a 
much simpler matter mechanically than with ruminants. 
Chemically, the results are essentially similar, i. e., the 
protein is in part changed to peptones. The food, after 

H 



114 



The Feeding of Animals 



being swallowed, is not returned to the mouth, but is 
very soon brought under the action of the gastric juice 

without so long -continued pre- 
liminary preparation by remas- 
tication and trituration . For 
this reason the horse fails to 
digest coarse fodders so com- 
pletely as the ox does. Besides, 
the stomachs of the horse and 
pig are too small to admit of 
so large an ingestion of hay or 
similar material, as is the case 
with ruminants of similar size. 
a, pyloric end of stomach, with In all species, however, the 

beginning of small intestine. chemical regult Q f stomach 

digestion is essentially the same, i. e., the protein is in 
part changed to peptones. Fig. 2. 




Fig. 2. Stomach of horse. 
B, cesophagal attachment. 



THE INTESTINES 

The most extended portion of the alimentary canal, 
though not the most capacious in all cases, is the in- 
testines. They consist of a tube differing in size in its 
various portions, which begins with the stomach and 
ends with the anus. This tube is not a straight passage 
between the points named, but presents curves and 
folds, so that when straightened out it appears sur- 
prisingly long. Its average length with the ox is given 
as 187 feet, sheep 107 feet, horse 98 feet, and hog 
77 feet, lengths which are from twelve to twenty - 
seven times that of the body of the animal. The intes- 



Digestion — The Intestines 115 

tines are divided into large and small, the latter being 
from three to four times as large as the former. 

When the food leaves the stomach, it enters the 
small intestines. At this point it is only partially 
digested. The fats are probably so far unchanged and, 
without doubt, the larger proportion of the proteids 
and carbohydrates that are susceptible of solution is 
still in the original condition. Hardly has this par- 
tially dissolved material passed into the small intes- 
tines before it comes in contact with two new liquids 
which are poured upon it simultaneously or nearly so; 
viz., the bile and the pancreatic juice, and the changes 
which began in the mouth and stomach, together with 
others which set in for the first time, proceed vigor- 
ously. 

The bile has its source in the liver. It is a secre- 
tion of this organ, and after elaboration it is stored in 
a small sac attached to the liver which is called the 
"gall bladder," and from which gall is conveyed to 
the intestines through a duct opening very near the 
orifice leading out of the stomach. Bile is a liquid 
varying when fresh from a golden red color in man 
to a grass -green or olive -green in certain herbiverous 
animals. It is slightly alkaline, bitter to the taste 
and without odor. The specific and characteristic con- 
stituents of the bile are two acids, glycocholic and 
taurocholic, that are combined with sodium and are 
associated with two coloring matters, bilirubin and 
biliverdin. Numerous other compounds are present 
in very small proportions, such as fats, soaps and min- 
eral compounds, but they appear to have no important 



116 The Feeding of Animals 

relation to digestion. If any ferment is present at all, 
it is only as a trace, and therefore the bile is incapable 
of effecting decomposition of the proteids and carbo- 
hydrates, such as occur in the mouth and stomach. 
This is shown by experiments. 

Nevertheless, this liquid must be regarded as having 
a real digestive function, which it exerts in two ways, 
(1) by preparing the chyme (partially digested food 
from the stomach) for the action of the pancreatic juice 
and (2) in acting upon the fats in such a way as to 
render their absorption possible. 

We have learned that pepsin, the stomach ferment, 
acts upon proteids only in an acid medium. The oppo- 
site is true of the ferments which the food meets in the 
intestines, for these require an alkaline condition. The 
bile tends to neutralize the acidity of the chyme, and in 
this, as well as by other chemical changes too complex 
for discussion here, prepares the way for the pancreatic 
juice to do its work. 

The most important discovery so far made in con- 
nection with the bile is the fact that when its entrance 
into the intestines is prevented the fat of the food 
largely passes off in the feces. This proves that in 
some way the liver secretion is essential to the digestion 
of fats. The ordinary and probably correct explanation 
of what takes place is that, while bile does not decom- 
pose the fats in any way, it is able, in connection with 
certain influences of the pancreatic juice, to reduce them 
to an emulsion, i. e., to a condition of suspension in a 
liquid in very finely divided particles, a form in which 
they are able to pass into the blood. It is believed 



Digestion — Intestines 117 

that the bile has more or less antiseptic influence and 
so prevents the intestinal contents from undergoing 
putrefactive fermentation, which would have the effect 
of greatly increasing the offensive odor of the feces. 

The pancreatic juice has a more complex function 
in digestion than that of any other digestive fluid. It 
is known to contain at least three distinct ferments, 
each of which has its own peculiar effect upon each of 
the three classes of food constituents. This juice reaches 
the food at practically the same time as the bile. It 
comes from the pancreas, a gland known to butchers 
as the "sweet bread," and enters the intestine through 
a small duct which in some animals is confluent with 
the bile duct. It is somewhat gluey in character, of 
alkaline reaction and has a saltish taste. 

First of all, the pancreatic juice has, in a marked 
degree, the power of digesting proteids in an alkaline 
medium. This power is due to a ferment known as 
trypsin, which converts proteids to peptones, and cor- 
responds in its function, therefore, to the pepsin of 
the stomach. Under the influence of this ferment the 
proteids are also, to some extent, split into simpler 
bodies. 

The transformation of starch into sugar and other 
soluble bodies, which ceased in the stomach, is again 
taken up through the influence of a diastatic ferment 
present in the pancreatic juice, and proceeds vigorously. 
A third enzym, also present, is one that has the power 
of splitting the neutral fats into fatty acids and glycer- 
ine, a change which appears to have an important rela- 
tion to the emulsionizing of fats. As before intimated, 



118 The Feeding of Animals 

the bile and the pancreatic juice appear to share the 
function of fat digestion. 

As the intestinal contents pass along-, they come in 
contact with a juice secreted by the walls of the intes- 
tines, the action of which has been carefully studied. 
It has been found that this liquid has no action on the 
proteids or fats, but that it is able to convert starch 
into soluble bodies, and especially has the peculiar prop- 
erty of transforming into glucose the maltose arising 
from previous digestion, glucose being the form in 
which all digested carbohydrates are supposed to enter 
the circulation. It seems, then, that the intestinal juice 
supplements the action of the other digestive fluids, so 
far as carbohydrates are concerned, completing starch 
digestion and preparing the sugars for absorption, and 
when we consider that from 80 to 90 per cent of the 
food of our farm animals consists of carbohydrates the 
great importance of this office is apparent. 

From the time the food enters the stomach until the 
undigested residue leaves the bod}^ the contents of the 
alimentary canal are subjected to fermentations caused 
by organized ferments, resulting in the evolution of 
acids, gases and certain other compounds formed from 
the proteids, which give to the feces its offensive odor. 
Just what relation these fermentations have to the di- 
gestion of food we are not able to state. There are 
strong reasons for believing that crude fiber (cellulose), 
during its stay in the first stomach, is the subject of 
their action, and its digestion may be wholly brought 
about in this way. Such fermentations become promi- 
nent only when, because real digestion does not proceed 



Food Absorption 119 

normally, they are given an opportunity to develop with 
unusual activity and cause bloat, colic and offensive 
odors in the solid excrement. 

ABSORPTION OF THE FOOD 

From the time the food enters the stomach, during 
nearly its entire course along the alimentary canal, there 
is a constant production of soluble compounds, which 
progressively disappear into other channels, so that when 
the anus is reached only a portion of the original dry 
matter is found in the residue. In some way, not wholly 
explainable in all its details, the digested food has been 
absorbed and received into vessels through w T hich it is 
distributed to the various parts of the body. 

A merely casual observation shows us that the inner 
surface of the walls of the digestive organs are covered 
by numerous projections. The anatomist, by a careful 
study of these, has learned that imbedded in their tis- 
sue, especially in the intestines, are the minute branches 
of two systems of vessels. One set is the lacteals be- 
longing to the so-called lymphatic system and the other 
set is the capillaries of the blood system. The lym- 
phatic vessels or tubes all lead to a main tube or reser- 
voir, the thoracic duct, which extends along the spinal 
column and finally enters one of the main blood-vessels. 
Any material, therefore, taken up by the lacteals ulti- 
mately reaches the blood. The capillaries all converge 
to a larger blood-vessel, known as the portal vein, which 
enters the liver, carrying with it whatever material the- 
capillaries have absorbed. 



120 The Feeding of Animals 

The manner in which the soluble food is absorbed 
may be explained in part on common physical grounds. 
When two solutions of different densities, containing 
diffusible compounds, are separated by a permeable 
membrane, diffusion through this membrane from the 
denser to the lighter liquid will always occur. Such a 
condition as this prevails in the intestines, we may be- 
lieve. The intestinal solution, the denser one, is sep- 
arated from a less concentrated liquid, the blood, which 
is constantly flowing on the other side of a thin dividing 
membrane. Under these conditions only one thing can 
occur; viz., the passage into the blood of certain parts 
of the digested food. It is held that in this way w r ater, 
soluble mineral salts and sugar pass directly into the 
blood-vessels. The peptones are taken up largely by 
lacteals and the fats enter the blood entirely through 
this channel. 

In the absorption of peptones, we encounter forces 
other than those which pertain to the mere diffusion of 
liquids, the operation of which is still more or less 
shrouded in mystery. As we have learned, the proteids 
are largely changed to peptone in the stomach and in- 
testines, but, strange as it may seem, no peptone is 
found in the blood. At some point in its passage 
through the lining tissues of the digestive tract, it has 
been regenerated into forms more nearly like those from 
which it is derived. Moreover, the absorption of fats 
is regarded as being accomplished through the activity 
of certain cells or corpuscles, which appear to convey 
this portion of the food to the lacteals. It seems, then, 
that the vital forces residing in the living animal cells 



Undigested Residue — Why Digestibility Varies 121 

play a part in transferring the nutrients into the blood 
circulation, and that this absorption can no longer be 
explained wholly on physical grounds. 

FECES 

The soluble and insoluble portions of the intestinal 
contents become separated gradually, and the undissolved 
part arrives finally at the last stage of its journey along 
the alimentary canal and is expelled as the solid excre- 
ment or feces. This is made up of the undigested food 
and a small proportion of other matter, such as residues 
from the bile and other digestive juices, mucus and 
more or less of the epithelial cells, which have become 
detached from the walls of the stomach and intestines. 
Very small quantities of fermentation products are 
present also, which give to the feces its offensive odor. 
The incidental or waste products may properly be con- 
sidered as belonging to the wear and tear of digestion 

THE RELATION OF THE DIFFERENT FEEDING STUFF 
COMPOUNDS TO THE DIGESTIVE PROCESSES 

Numerous digestion experiments with a large variety 
of feeding stuffs have abundantly established the fact 
that these materials differ greatly in their solubility in 
the digestive juices. This is an important matter, and 
one which should be well understood, for we must con- 
sider both the weight of a ration and its availability 
in determining its nutritive value. Variations in diges- 
tibility are caused primarily by variations in composi- 



122 The Feeding of Animals 

tioii. The low digestibility of wheat straw, as compared 
with that of the wheat kernel, is due to the absence in 
one of compounds that are abundant in the other. We, 
therefore, must deal fundamentally with the suscepti- 
bility of the various single constituents of plants to the 
dissolving action of the several digestive ferments. 

In this connection, we need to pay little attention to 
the mineral compounds. They do not undergo fermen- 
tative changes in the way that the carbon compounds 
do, but pass into simple solution either in the water 
accompanying the food, or in the juices with which they 
come in contact. 

As has been noted, protein is a mixture of nitrog- 
enous compounds, largely albuminoids. The gluten of 
wheat contains at least five of these bodies, and other 
seeds as many. What is the relative susceptibility of 
these single proteids to ferment action either as to ra- 
pidity or completeness of change does not appear to be 
known. Some albuminoids are practically all digested 
by artificial methods, and probably are in natural di- 
gestion. It is a fact, however, that protein is much 
more completely dissolved from some feeding stuffs than 
from others. That of milk is all digestible, that of some 
grains very largely so, while with the fodders quite a 
large proportion escapes solution. Whether this is due 
to a differing degree of solubility on the part of the 
characteristic protein compounds of these feeding stuffs 
is not quite determined. The fact that highly fibrous 
materials show the lowest proportion of digestible pro- 
tein suggests as an explanation that the nitrogen com- 
pounds of the coarse fodders are so protected by the 



7\luj Digestibility Varies 123 

large amount of fiber present that they escape the 
full action of the digestive juices. It is certain, anyway, 
that the protein of young and tender tissues and of the 
grains is more fully digested than that of the hays and 
straws. 

In the case of the carbohydrates, our knowledge of 
the relative susceptibility of the individual compounds 
to enzym action is more definite. First of all, the nec- 
essary modification of the sugars, which are already 
soluble, is slight, and they are wholly digested. In the 
second place, we have learned in two ways that the 
starches are wholly transformed to diffusible compounds, 
first by submitting them in an artificial way to the ac- 
tion of various diastatic ferments, and, second, by dis- 
covering a complete absence of starch or its products in 
the feces of our domestic animals. In no case that has 
come under the writer's notice has either starch or sugar 
been found in the solid excrement. We can say, there- 
fore, that under normal conditions the starches, like the 
sugars, are completely digestible. 

Digestibility must be considered, however, from the 
standpoints both of rapidity and of completeness. As 
to the former factor, starches from unlike sources ex- 
hibit some remarkable differences. Investigations by 
8 tone, who submitted a. number of these bodies to the 
action of several diastatic ferments, show that "this 
variation reaches such a degree that under precisely the 
same conditions certain of the starches require eighty 
times as long as others for complete solution." The 
potato starches appear to be acted upon much more 
rapidly than those from the cereal grains. 



124 The Feeding of Animals 

Other carbohydrates and related substances, such 
as the gums and cellulose, do not undergo complete 
digestion, sometimes half or more of these compounds 
escaping solution. Stone, after examining twenty feed- 
ing stuffs and the fecal residues obtained from them in 
digestion experiments, found in the feeding stuffs from 
6 to 16 per cent of gums, 46 to 77 per cent of which 
was digested, the average being 58 per cent. Crude 
fiber proves to be digestible within about the same 
limits, or 36 to 80 per cent with American fodders. We 
are much in the dark concerning the manner of diges- 
tion of the gums and crude fiber. To what extent 
these substances are the subjects of purely fermentative 
changes, or of merely chemical decompositions, is not 
known at present, but the fact of a partial digestion is 
well established whatever may be the causes involved. 

The extent of the digestion and absorption of the 
fats or oils is also not definitely known. If we were to 
accept the figures given for ether extract in tables of 
digestion coefficient as applying to the real fats we 
would believe that their digestibility varies from less 
than one -third to the total amount. It is unfortunately 
true that these coefficients mean but very little. The 
ether extract from the feeding stuffs is only partially 
fat or oil, as we have seen, and the inaccuracy of a 
digestion trial is still further aggravated by the pres- 
ence in the feces of bile residues and other bodies which 
are soluble in ether, so that the difference between the 
ether extract in the ration and that in the feces gives 
us little information as to what has happened to the 
actual fats. It seems very probable that pure vegetable 



Why Digestibility Varies 125 

fats and oils are quite completely emulsified and ab- 
sorbed. 

The foregoing statements make it plain that when 
the general composition of a feeding stuff is known it 
is possible to predict with a good degree of certainty 
whether its rate of digestibility is high or low. The 
larger the proportion of starch and sugar and the smaller 
the percentage of gums and fiber, the more complete 
will be the solution. We see this illustrated in the ex- 
treme by the difference in digestibility of corn meal and 
of wheat straw. 



«#•**> 



CHAPTER IX 

CONDITIONS INFLUENCING DIGESTION 

The chemical changes and other phenomena consti- 
tuting* digestion, which have been described as occurring 
in the alimentary canal, are practically outside the con- 
trol of the one who feeds the animals. They proceed 
in accordance with fixed chemical and physiological 
laws. It is, however, within the power of the feeder 
to so manipulate the food or vary the conditions under 
which it is fed that the extent or completeness of diges- 
tion is modified, and this must be regarded as an im- 
portant matter when we remember that only the digested 
food is useful. 

PALATABLENESS 

It is entirely reasonable to believe that a thorough 
relish for food is conducive to good digestion. The 
secretion of the digestive juices is not a mechanical 
process, but is under the control of the nervous system. 
With man, at least, the enjoyment of eating, even its 
anticipation, stimulates the secretory power of the sal- 
ivary glands and those in the mucus lining of the 
stomach, and it is evident that this holds true with 
animals. Palatableness is, therefore, an important fac- 
tor in successful feeding, for it tends to promote a 

(126) 






Influence of Palatableness, Quantity 127 

state of vigorous activity on the part of the digestive 
organs. The experienced feeder knows well the value 
of stimulating the appetite of his animals by means of 
attractive mixtures. An agreeable flavor or taste adds 
nothing to the energy or building capacity of a food, 
but it does tend to secure a thorough appropriation of 
the nutrients which enter the alimentary canal. With- 
out doubt, the success of one feeder as compared with 
the failure of another may sometimes be due, in part, 
to a superior manner of presenting a ration to the 
animal's attention and to manipulations that add to 
the agreeableness of its flavors. 

INFLUENCE OF QUANTITY OF RATION 

Early experiments by Wolff, in which he fed larger 
and smaller rations of the same fodder to the same 
animals, have been made the authority for the state- 
ment that a full ration is as completely digested as a 
scanty one, provided the former does not pass the nor- 
mal capacity of the animal. It must be said, however, 
that the testimony concerning this point is not unani- 
mous. Since Wolff's experiments, Weiske, in feeding 
oats to rabbits, found the digestibility to be inversely 
as the quantity of food taken. In experiments with 
oxen, by G. Kiihn, at Mockern, when the grain ra- 
tion was doubled the digestibility of the malt sprouts 
used was decreased about nine per cent. Results at 
the New York Experiment Station from feeding full 
and half rations to four sheep showed uniformly higher 
digestion coefficients with the smaller ration, the differ- 



128 • The Feeding of Animals 

enees being too large and too constant to be considered 
accidental. Other experiments give varying and con- 
flicting figures. If we assume that the constituents of 
feeding stuffs have a certain fixed solubility in the di- 
gestive fluids, then within reasonable limits the amount 
of food should have no effect upon the proportions of 
nutrients digested, but such an assumption cannot safely 
be made. 

Doubtless no single statement concerning this point 
will be found applicable to all animals and all rations. 
Certainly, overfeeding may lessen the extent of solution 
and is never wise, while under -feeding for the sake of 
securing a maximum digestibility would not be good 
practice. It is reasonable to suppose, however, that 
the relation in quantity between the enzj^ms and the 
food compounds has an influence, at least, upon the 
rapidity of digestion ; and indeed investigations by 
Stone very strongly point to such a conclusion, for he 
found that the rate of ferment action was proportional 
to the concentration of the ferment solution. 

EFFECT OF DRYING FODDERS 

At one time the belief became very firmly fixed in 
the public mind that curing a fodder causes a material 
decrease in its digestibility. Because this drying is 
often carried on under conditions that admit of de- 
structive fermentations or of a loss of the finer parts 
of the plant, this view is probably correct for partic- 
ular cases, but if it is accomplished promptly and in 
a way that precludes fermentation or loss of leaves it is 



Treatment of Fodders 129 

doubtful if curing has any material effect upon digesti- 
bility. 

The point has been the object of six American di- 
gestion experiments, Hungarian, timothy, pasture grass, 
corn fodder, crimson clover and winter vetch being the 
experimental foods. With four of these slight, but un- 
important, differences were observed in favor of the 
dried material, while the reverse was decidedly true of 
the crimson clover and the corn fodder. German ex- 
periments show in a majority of cases greater digesti- 
bility for the green fodders. It seems probable that 
in general practice, because of greater or less unavoid- 
able fermentation and a loss of the finer parts of the 
plant, dried fodders have a somewhat lower rate of 
digestibility than the original green material, a fact 
not due directly to drjdng, but to a decrease, either 
of the more soluble compounds or of the tender tissues. 

INFLUENCE OF THE CONDITIONS AND METHODS OF 
PRESERVING FODDERS 

Iii comparing the conditions and methods of pre- 
serving fodders in their relation to digestibility, we may 
safely rest upon the general statement that when, for 
any cause, leaching occurs or fermentations set in, di- 
gestibility is depressed. The explanation of this state- 
ment is that those compounds of the plant which are 
entirely soluble in the digestive fluids, notably the 
sugars, are the ones wholly or partially removed or 
destroyed by leaching or fermentations, while the more 
insoluble bodies remain unaffected. When, therefore, 
hay is cured under adverse conditions, such as long -con- 



130 . The Feeding of Animals 

tinued rain, digestibility is decreased, and the same effect 
is inevitable from the changes which occur in a ferment- 
ing mass, such as a mow of wet hay, a pile of corn- 
stalks or the contents of a silo. Experimental evidence 
of the truth of these statements is not wanting. Ger- 
man digestion trials with alfalfa and esparsette, green, 
carefully dried, cured in the ordinary way, fermented 
after partial drying and as silage, show a gradually 
decreasing digestibility from the first condition to the 
last. A single American experiment, comparing the 
same fodder both green and as silage, gives testimony in 
the same direction. On the other hand, field -cured corn 
fodder, according to nine out of eleven American ex- 
periments, is considerably less digestible than silage 
coming from the same source. Here it is largely a 
question of the relative loss by fermentation in the two 
cases, and it is t.o be expected that the outcome would 
not be wholly one way. 

INFLUENCE OF THE STAGE OF GROWTH OF THE PLANT 

Another generalization, which certainly must hold 
good with reference to the digestibility of fodder plants, 
is that any conditions of development which favor a 
relatively large proportion of the more soluble carbo 
hydrates; viz., starches and sugars, and secure a min- 
imum of gums and fiber, promote a high rate of diges- 
tibility, and reverse conditions produce the opposite 
result. It is well known that, in general, as the meadow 
grasses mature the relative proportion of fiber increases 
and the tissue becomes harder and more resisting. Nu- 



Stage of Growth, Preparation 131 

merous American and European digestion trials unite in 
testifying almost unanimously to a gradually diminished 
digestibility as the meadow grasses increase in age. 
The maturing of maize seems to produce quite the con- 
trary effect. The testimony of experiments conducted 
at the Connecticut, Maine and Pennsylvania Experiment 
Stations justifies the statement that the corn plant, cut 
when the ears are full grown, furnishes not only a larger 
amount of digestible material, but a larger relative pro- 
portion than when cut before the ears have formed; 
and this is strictly in harmony with our general prin- 
ciple; for the mature plant, on account of the storage 
of starch in the kernels, has by far a larger proportion 
of the more digestible carbohydrates. 

INFLUENCE OF METHODS OF PREPARATION OF FOOD 

Much labor and expense have been expended by 
farmers in giving to feeding stuffs special treatment, 
such as wetting, steaming, cooking and fermenting, in 
order to secure a supposed increase in nutritive value, 
an increase which must come chiefly, if at all, from a 
more complete digestion. It is plainly noticeable that 
these methods of feeding have lost in prevalence rather 
than gained. Practice does not seem to have perma- 
nently ratified them, and, so far as digestibility is 
concerned, this outcome is in accordance with the re- 
sults of scientific demonstration. The conclusions of 
German experimenters have been that these special 
treatments have no favorable influence, their effect 
being either imperceptible or unfavorable. 



132 • The Feeding of Animals 

It should occasion no surprise that the mere wetting 
of a food is without influence upon its solubility in the 
digestive juices, because it becomes thoroughly mois- 
tened during mastication and in the stomach. It is 
not rational to expect that previous wetting would have 
the slightest effect unless it induced more complete 
mastication, which certainly would not be the case with 
ground grains. The extensive trials by Kiihn and 
others with a hay and bran ration, the bran being fed 
in several conditions, such as dry, wet, moistened some 
hours before feeding, treated with boiling water and 
fermented, gave results adverse to all of the special 
methods of preparation as either useless or harmful, 
and no testimony so thorough and convincing has been 
furnished on the other side. 

German and American experiments unite in con- 
demning the cooking of foods already palatable, because 
this causes a marked depression of the digestibility of 
the protein, with no compensating advantages. Diges- 
tion trials with cooked or steamed hays, silage, lupine 
seed, cornmeal and wheat bran, and roasted cotton 
seed, uniformly show their protein to be notably less 
digestible than that in the original materials, a fact 
which may explain the lessened productive value of 
cooked grains which has been observed in certain ex- 
periments. It must be conceded, of course, that 
when cooking feeding stuffs by steaming or otherwise 
renders them more palatable, and thereby makes pos- 
sible the consumption of material otherwise wasted, 
the influence upon digestibility is a minor consid- 
eration. 



Influence of Grinding and of Salt 133 

INFLUENCE OF GRINDING 

Few points are more frequently questioned than the 
profitableness of grinding grain. There seem to be 
only two ways in which such preparation can enhance 
the nutritive value of a feeding stuff; viz., by dimin- 
ishing the energy needed for the digestive processes 
and by increasing the digestibility. While only about 
a half-dozen experiments bearing upon the digestion 
side of this question are on record, their evidence is 
quite emphatic. In three trials with horses, with both 
corn and oats, grinding caused an increase of digesti- 
bility varying from 3.3 to 14 per cent. A single 
experiment with maize kernels gave a greater diges- 
tibility of about 7 per cent from grinding, and with 
wheat, in one trial, the increase was 10 per cent. In 
one test of oats with sheep, the unground kernels were 
as completely utilized as the ground. It is reasonable 
to expect that with ruminants the danger of imperfect 
mastication is less than with horses and swine, although 
whole kernels of grain are often seen in the feces of 
bovines. The profitableness of grinding grain Hums, in 
part at least, upon the relation of the cost of grinding to 
the loss of nutritive material from not grinding. If the 
miller's toll amounts to one-tenth the value of the grain 
the economy of grinding it may be doubtful, especially 
with ruminants. 

EFFECT OF COMMON SALT 

It is the custom of many feeders to allow their ani- 
mals an unlimited supply of salt, and others furnish it 



134 • The Feeding of Animals 

in definite and regular quantities. The belief prevails 
more or less widely that an abundant consumption of 
salt is beneficial. If this is true, the advantage arises 
for other reasons than an increased digestibility. The 
verdict from earlier experiments by Grouveu, Hofmeis- 
ter and Weiske that the addition of salt to the ration 
does not increase the digestibility has been confirmed 
by more recent tests by Wolff. Indeed, if we give to 
the data collected a literal and perfectly justifiable in- 
terpretation, salt diminished rather than raised the 
proportion of digestible nutrients. 



INFLUENCE OP FREQUENCY OF FEEDING AND WATERING 

ANIMALS 

Few experiments relative to this point are on rec- 
ord. One by Weiske and others, relative to frequency 
of feeding, and another by Gabriel and Weiske, in 
which the effects of the time of watering and of the 
amount of water were tested, give no indication that 
the completeness of digestion is materially affected by 
variations in these details of practice. It seems proba- 
ble that the nutritive importance of these minor points 
in managing animals has been much overestimated by 
some, especially as affecting the utilization of the food. 

INFLUENCE OF CERTAIN OTHER CONDITIONS " 

It is well known that the composition of fodder 
crops grown on the same soil may vary somewhat from 
year to year according as the season is wet or dry, cold 



Combination of Nutrients 135 

or warm. Such variations may influence digestibility, 
though no actual demonstration of this fact appears to 
be on record. The question is often asked whether the 
storage of hay for a long period affects its nutritive 
value. The data from four series of experiments 
touching on this point indicate that there is a per- 
ceptible, though not marked, decrease in digestibility of 
hay during long -continued storage. 

INFLUENCE OF THE COMBINATION OF FOOD NUTRIENTS 

Among the apparently important and freely ex- 
ploited conclusions drawn from investigations in ani- 
mal nutrition is the statement that the digestibility of 
food is influenced to a marked degree by the relative 
proportions of the several classes of nutrients. It is 
taught that if more than a certain percentage of starch 
and sugar, or of feeding stuffs rich in carbohydrates, 
like potatoes or roots, is added to a basal ration, the 
digestibility of the latter is decreased, the protein and 
fiber being especially affected. The conclusions, as 
stated by Dietrich and Konig, on the basis of a criti- 
cal study of the data involved are that if pure carbo- 
hydrates are used to the extent of more than 10 per 
cent of the dry substance of a basal ration, or if pota- 
toes and roots are fed equivalent in dry matter to 
more than 15 per cent, a depression of digestibility 
occurs, which increases with the amount of carbo- 
hydrate material added. A modifying conclusion is, 
that if the addition of the carbohydrate material is 
accompanied by correspondingly more protein, the de- 



136 . The Feeding of Animals 

pressiou of the digestion coefficients is much lessened 
or does not occur. Many data are cited in support of 
these generalizations which are worthy of careful con- 
sideration. 

It is not unreasonable to suppose that the relative 
quantity in a ration of the several classes of nutrients 
may have an influence upon the digestive processes, 
and we should accept the verdict of previous observa- 
tions in so far as they will bear critical discussion and 
further investigation. It should be said in the first 
place, by way of comment, that the carbohydrate ma- 
terial in the experiments cited has usually been fed in 
addition to a basal ration, thus increasing the amount 
of food consumed, and, as we have seen, this may have 
an influence upon the proportion of total diy matter 
digested. In this particular, the experiments have not 
been logical. 

In the second place, in these experiments, no allow- 
ance has been made for the metabolic nitrogen in the 
feces, i. e., that not belonging to the true undigested 
residue. As this appears to be independent of the 
amount of protein fed and stands more nearly in rela- 
tion to the total digested nutrients, it follows that the 
smaller the proportion of protein in the digested food, 
the larger the error caused by the waste nitrogen 
products. A careful study of this point in the light of 
more recent knowledge might modify the conclusion 
reached as to the depression of protein digestion 
through feeding starch or starchy foods. In all or 
nearly all the experiments where this effect is appar- 
ently shown the digestible dry matter of the ration 



Digestion — Influence of Animal 137 

was largely increased and the protein remained con- 
stant or was diminished. The depression of the di- 
gestibility of the crude fiber is not easily explained 
on any other ground than that of the influence of the 
greater proportion of starch. 

What is claimed as the effect of a dispropor- 
tionate addition to the supply of carbohydrates does 
not appear to be true of a similar increase in the 
ration of fat and easily digested protein. Several ex- 
periments in which oils and albuminoids have been 
added freely to a basal ration did not indicate that 
such addition had any material effect upon digesti- 
bility. 

CONDITIONS PERTAINING TO THE ANIMAL: SPECIES, 
BREED, AGE, AND INDIVIDUALITY 

The conclusion reached by the early experimenters 
in the field of animal nutrition that the digestive effi- 
ciency of the several species of ruminants was prac- 
tically uniform, has not been set aside by more recent 
observations. The number of experiments upon which 
this conclusion was based was large, and their verdict 
is not likely to be reversed by observations less ex- 
tensive or less complete. 

The following coefficients were obtained from Ger- 
man trials with meadow hay: 

Dry substance digested from meadow hay (per cent) 

Samples Best Medium Poor 

Sheep 42 67 61 55 

Oxen 10 67 64 56 

Horse 18 58 50 46 



138 The Feeding of Animals 

Nine American experiments have been the means of 
studying results with large and small ruminants, steers 
being compared with sheep and cows with goats. In 
five cases, the large animal digested from 5 to 14 per 
cent the more, in three cases the excess for the small 
animal varied between 7 and 17 per cent, and in one 
case there was little difference. The general effect of 
such conflicting results is to confirm the older and 
more numerous observations. 

The horse and ruminants differ in digestive ca- 
pacity to a marked extent. The comparisons which 
have been made show a uniformly lower digestive effi- 
ciency for coarse fodders on the part of the former. 
It appears that because of less perfect mastication, or 
for some other reason, the horse dissolves much less 
of the crude fiber than the steer or sheep, and the 
effect of this is prominent with hays and other fibrous 
materials. With the grains, ruminant and equine diges- 
tion are not greatly unlike, eight samples of oats with 
sheep and twenty -four with the horse showing almost 
identical digestion of the dry matter. With maize the 
case is the same. In experiments with beans, the ad- 
vantage was slightly with the ruminant. So far as 
we are able to judge, swine digest concentrated food 
about as do ruminants and the horse. How this is 
in the case of the fodders we do not know fully, 
but it is proven that the swine digest crude fiber quite 
freely. 

Past experiments have not revealed any influence of 
breed upon digestive capacity. There is no reason for 
supposing that Shorthorn cattle, Southdown sheep and 



Digestibility — How Determined 139 

Chester White pigs would digest rations differently from 
Jerseys, Merinoes and Yorkshires. 

Young animals seem to digest high quality coarse 
foods and grains as efficiently as older ones of the same 
species, which is probably contrary to the popular belief. 
There is doubtless a variation in the digestive power of 
individual animals, but the data so far collected do not 
show this with any degree of definiteness. In those in- 
stances where the same four or more steers or sheep 
have been used in determining the digestibility of sev- 
eral feeding stuffs the highest coefficients were obtained 
sometimes with one animal and sometimes with another. 

DETERMINATION OF DIGESTIBILITY 

If we accept as the undigested food the dry matter 
of the solid excrement, which is practically in accor- 
dance with the fact, we have only to subtract this fecal 
residue from the dry matter of the ingested food in order 
to ascertain the amount and proportion digested. All 
digestion experiments have proceeded on this basis. 
Animals have been fed at regular intervals a uniform 
quantity of carefully analyzed food and the feces have 
been collected, weighed and analyzed. From the data 
thus obtained, the digestion coefficients have been cal- 
culated. The method and the mathematics of such 
experiments are so simple that correct results seem very 
easy to obtain and they do possess an accuracy suffi- 
ciently approximate to truth to render them useful in 
practice. As digestion trials are usually conducted, the 
coefficients of digestibility obtained for the dry matter 



140 The Feeding of Animals 

and total organic matter represent, we have reason to 
believe, very nearly the actual digestible matter in the 
particular material studied. The proportions secured 
for particular classes of nutrients may be less accurate, 
for reasons that will appear. We cannot be sure, either, 
that the digestibility of one hay applies to another 
produced and cured under totally different conditions. 
The truth of this latter statement is clearly seen in the 
effect of the various factors upon digestibility. 

The inaccuracies of digestion coefficients are chiefly 
in those for protein and fats. Let us see how and why 
this is. The errors in the figures for protein are caused 
by the presence in the feces of nitrogen compounds 
which are not a part of the undigested food protein. 
These are waste compounds which are residues from the 
bile and other digestive juices, epithelial cells and mucus 
which are carried along from the walls of the intestines 
during the passage of the food. Their quantity seems 
not to be proportional to the protein fed, but appears 
to be influenced more or less by the amount of food 
digested. Their source is the "wear and tear" of the 
digestive apparatus. It follows then that the less pro- 
tein there is in a ration, the larger the percentage error 
caused by these metabolic products. In certain experi- 
ments with oat straw, the fecal nitrogen has been more 
than that of I he food, although without question much 
of the straw protein was digested. It has been found, 
using the best methods known for extracting these waste 
products, that they cause a much larger error for the 
protein of the straws than for that of the legume hays. 
It is probably safe to affirm that at least ten should 



Digestibility — How Determined 141 

be added to the coefficients of digestibility of the pro- 
tein of coarse fodders as usually given in the tables that 
have been compiled. 

Errors are caused in determination of the digesti- 
bility of fat in much the same way. Certain of the bile 
residues in the solid excrement are soluble in the ether 
which is used to extract the fats, and consequently the 
undigested fat appears to be larger than it really is. 



CHAPTER X 

THE DISTRIBUTION AND USE OF THE DIGESTED FOOD 

The digested food, after absorption, all passes into 
the blood, either directly or indirectly, and mixes with 
it. The materials which are to serve the purposes of 
nutrition are now taken up by a stream of liquid that is 
in constant motion throughout the minutest divisions 
of every part of the animal. Flowing in regular chan- 
nels the blood reaches not only the bones and muscular 
tissues, but it passes through several special organs and 
glands where the nutrients it is carrying and certain 
of its own constituents meet with profound changes. 
It is here that we discover the manner in which food 
is applied to use and what are some of the transforma- 
tions which the proteids, carbohydrates and fats under- 
go in performing their functions. 

In order to follow intelligently this most interesting 
phase of nutrition, we must know something of the 
blood and of the organs — the lungs, liver and kidneys 
— through which it passes. 

THE BLOOD 

The blood, when in a fresh state, is apparently 
colored and opaque, but if a minute portion is ex- 

(142) 



Blood and its Functions 143 

amined with a microscope, it is seen to be a compar- 
atively clear liquid in which float numerous reddish, 
disk - like bodies. These bodies, which are known 
as corpuscles, give to the blood its bright red color. 
The liquid in which they are suspended is called the 
plasma. 

The corpuscles are not mere masses of unformed 
matter, but they are minute bodies having a definite 
form and structure. They make up from 35 to 40 per 
cent of the blood, and contain over 30 per cent of dry 
matter. This dr}~ matter consists mostly of haemo- 
globin, a compound that is peculiar to the blood and 
equips it for one of its most important offices. Haemo- 
globin, as before stated, is made up of a proteid (globin) 
and a coloring matter (haematin), in the latter of which 
is combined a definite proportion of iron. The peculiar 
property of this compound, which renders it so useful 
a constituent of the blood, is its power of taking up 
oxygen and holding it in a loose combination until it 
is needed for use. When thus charged, it is known 
as oxyhemoglobin. Because of this function of their 
most prominent constituent, blood corpuscles become 
the carriers of oxygen to all parts of the body. There 
are reasons for believing that they are also chiefly con- 
cerned in gathering up one of the waste products of 
the nutritive changes, viz., carbon dioxid, and convey- 
ing it to the points where it may be thrown off from 
the body. 

The plasma is about nine-tenths water, so that it 
easily holds in solution whatever soluble nutrients are 
discharged into it from the alimentary canal. Among 



144 The Feeding of Animals 

its constituents are found members of all the classes 
of compounds that are important in this connection, — 
ash, protein, carbohydrates and fats. The proportion 
of ash is about 1 per cent, three-fourths of it being 
common salt, and the remainder consisting of phos- 
phoric acid, lime and other important mineral com- 
pounds. The solid matter of the plasma is rich in 
albuminoids, including the fibrinogen which is the 
mother substance of fibrin and several albumins and 
globulins. These proteids make up about 80 per 
cent of the total dry substance of plasma. Sugar and 
fats are also present, their proportions varying with 
the extent to which they are being absorbed from the 
digestion of food. It is evident that the blood is 
charged with those materials which we recognize as 
necessary to the construction and maintenance of the 
animal body. 

THE HEART 

In quantity, the blood is from 3 to 4 per cent of 
the total weight of the live animal. It is contained in 
the heart and in two sets of vessels, one set called the 
arteries leading from the heart by various ramifications 
to all parts of the body, and the other set called the 
veins, leading from all parts of the body back to the 
heart. Through these vessels the blood is moving in 
a constant stream, which we call the circulation. It 
does not move of itself, but is forced along by a very 
powerful pump, the heart. This is a highly muscular 
organ divided into four chambers, which are separated 
by valves and partitions, the two upper chambers be- 



Work of the Heart 145 

ing called the right and left auricles, and the two 
lower the right and left ventricles. The right auricle 
is above the right ventricle and is separated from it 
by a valve, and the same is true of the left auricle 
and ventricle. Out of the left ventricle the blood is 
pumped into the arteries and after reaching the arte- 
rial capillaries throughout the entire body, it passes 
from these into the smallest divisions of the veins and 
comes back to the heart along the venous system, en- 
tering the right auricle. It is then carried to the 
lungs by way of the right ventricle and is returned to 
the left auricle to be sent to the left ventricle, and 
from there to again start on its journey through the 
body. The principal facts pertaining to the blood and 
its circulation have been reviewed in this simple man- 
ner as an aid to the discussing of other considerations 
somewhat pertinent to our subject. 

The nutrients, as prepared for use by digestion, 
enter the blood on its return flow to the heart, com- 
ing into the venous cavity by way of the hepatic 
(liver) vein and the thoracic duct as previously de- 
scribed. When, therefore, the right side of the heart 
is reached, a new accession of food material is on its 
way to sustain the various functions of nutrition. 

We are more interested in the object of blood cir- 
culation than we are in its mechanism. Somehow the 
digested food disappears into these constantly moving 
blood currents, and the only evidence of its effect 
which comes to us from ordinary observation is the 
warmth, motion and perhaps growth of the animal that 
is nourished. 



146 The Feeding of Animals 

THE LUNGS 

The first point where important changes occur is the 
lungs. Here the blood loses the purplish hue which 
it always has after being used in the body tissues 
and takes on a bright scarlet, a phenomenon that is 
more easily understood when we understand the lung 
structure. 

Breathing is a matter of common experience. We 
all know how air is drawn into the lungs at regular 
intervals, an equivalent quantity being as regularly 
forced out. The mechanism of respiration (breathing) 
we will not discuss at length. It will aid us, however, 
if we know that the passage which the air follows to and 
from the lungs, the trachea (windpipe), divides into two 
branches, one to each lung, and these divide and sub- 
divide until thejr branch into numerous fine tubes. 
Each of these tubes ends in an elongated dilation which 
is made up of air cells opening into a common cavity. 
These cells are so numerous in the lung tissues that only 
a very thin wall separates adjoining ones, and in this 
wall are carried the capillaries or fine divisions of the 
blood-vessels leading from the heart. This arrange- 
ment permits the blood to take up oxygen as it flows 
along and transfer certain wastes into the lung cavities, 
and thus be made ready to go back to the body carry- 
ing a joint load of digested food and oxygen. Of course 
the air that passes out of the lungs is less rich in 
oxygen than when it was taken in, and there have 
been added to it certain materials which we will notice 
later. 



Changes of Food in the Tissues 147 

THE USE OF FOOD 

The revivified blood now passes to all parts of the 
body and is brought into the most intimate relation with 
the minutest portion of every tissue. Several things 
happen in the course of time. 

In the first place, the new supply of nutritive sub- 
stances is used by the living cells in a way we do not 
wholly understand to rebuild worn-out tissue and to 
form new growth. With the young animal, much 
material is appropriated in the latter way. In the case 
of the milch cow, there is furnished to the udder the 
nutrients out of which the milk is formed through 
the special activities of that gland. 

Moreover, it is in the tissues that the oxygen which 
was taken up in the lungs is used to slowly burn a por- 
tion of the food. This combustion is believed not to 
take place by contact of the oxygen and food in the 
large blood-vessels, but it occurs by progressive steps 
throughout the minute divisions of the muscles and 
other parts of the whole body. Notwithstanding this 
oxidation may be very gradual and occupy much time, 
its ultimate products are, for the most part, similar to 
those which result from the rapid combustion of fuel. 
In the fireplace, starch, sugar, cellulose, fats and similar 
bodies would be burned to carbonic acid and water, and 
this is what takes place in the animal to the extent 
these nutrients are not used for growth. 

When the protein is not stored as such but is broken 
up, the result differs somewhat in the furnace and in 
the animal because in the latter the oxidation is not 



148 The Feeding of Animals 

complete. Here the proteids may be partially burned 
to carbonic acid and water, but a portion of their sub- 
stances passes from the body principally in the form of 
urea and uric acid, which are the prominent constituents 
of urine. These compounds carry with them a certain 
proportion of carbon and hydrogen which in ordinary 
fuel combustion would more fully unite with oxygen. 
The heat production from protein is therefore less in 
the animal than in the furnace. 

This oxidation in the animal is constant but not 
uniform. It varies with the exercise the animal is tak- 
ing and with the amount of food that must be disposed 
of. The quantity of oxygen needed is therefore vari- 
able, and when the demand for it is largely increased 
the heart pumps faster, more blood passes through 
the lungs, the breathing is more rapid and the supply 
of oxygen is in this way augmented. 

ELIMINATION OF WASTES 

The various waste products from this combustion 
and from the breaking up of the proteids within the 
animal evidently must be disposed of in some manner. 
If not eliminated from the body, they would cause re- 
sults of a most serious character, as, for instance, 
when an accumulation of urea in the body produces 
uraemic poisoning. The blood therefore not only carries 
to the tissues the necessary nutrients and oxygen, but 
it has laid upon it the burden of taking into its cur- 
rents the waste products of combustion and growth and 
carrying them to the points where they are thrown off. 



Disposition of the Wastes 149 

One of the branches of the arterial system of blood- 
vessels runs to the kidneys, and, by repeatedly rebranch- 
ing, traverses all their substance. The main function 
of the kidneys is to secrete the urine, a liquid in which 
all the waste nitrogen from the digested protein finds its 
way out of the body in the form of urea and similar 
bodies. The blood that enters them carries with it the 
urea and uric acid which have resulted from a break- 
ing down of protein, and in a most wonderful manner 
these compounds are filtered out so that they are not 
present in the outgoing blood. An excess of soluble 
mineral matters such as common salt is also removed 
by the kidneys, as well as the bile compounds which 
are absorbed from the alimentary canal. 

The carbon dioxid must in some way also be elimi- 
nated from the body. This is not accomplished to any 
extent until the blood containing it reaches the lungs, 
where it is exchanged for a new supply of oxygen and 
passes off in the expired air. In the case of man, the 
air "breathed out" is nearly a hundred times richer in 
carbonic acid than the air "breathed in." 

Water may be regarded from one point of view as 
a waste, for it is produced in the oxidation of the 
food, and this passes off from the lungs as vapor, 
through the skin as sensible or insensible perspiration, 
and in considerable quantities through the kidneys. 

To summarize, it may be said that the blood is con- 
stantly undergoing gain and loss. The gain comes 
from the food (including water and oxygen), and the 
loss consists of urea, carbonic acid and water given off 
through various channels. 



150 The Feeding of Animals 

THE LIVER 

One part of the arterial system of blood-vessels 
runs to the stomach and intestines and is distributed 
over their walls in fine divisions. These connect 
with the capillaries of the portal vein which leads to 
the liver. During this passage of the blood from 
one system to the other, it takes up digested food, 
chiefly sugar. Now it is very evident that the quan- 
tity of material thus absorbed must varj^ greatly at 
different times according to the nature and amount of 
food supply and the activity of the digestive processes. 
If, therefore, the blood from the alimentary canal was 
allowed to pass directly into the general circulation, 
the* supply to the tissues of the nutrients, especially 
the carbohydrates, would be very uneven. Just here 
comes in a liver function. In that organ there is 
found a starch -like body known as glycogen, which 
appears in increased quantity following the abundant 
absorption of sugar from the intestines. It is believed, 
because of this and other facts, that the liver acts as 
a regulator of the carbohydrate supply to the general 
tissues of the body, storing a temporary excess of the 
sugar in the form of glycogen and then gradually 
giving it up to the general circulation as it is needed. 



CHAPTER XI 

TEE FUNCTIONS OF THE NUTRIENTS 

The digestion, absorption and distribution of food 
are not its use, — they are the preliminaries necessary 
to use. Not until the nutrients have been converted 
to available forms and have passed into the blood do 
they in the slightest degree furnish energy or building 
material to the animal organism. We have followed 
to a certain extent the chemical changes which the 
digested food suffers, but no detailed statements have 
been made as to the part taken by each class of nutri- 
ents in constructing the animal body and in maintain- 
ing its complex activities. 

Animals use food in two general ways; viz., for 
constructive purposes, which involve the building or 
repair of tissue and the formation of milk, and as 
fuel for supplying different forms of energy, including 
heat. The tissues which are to be formed are of sev- 
eral kinds, principally the mineral portion of the bone, 
the nitrogenous tissue of the muscles, tendons, skin, 
hair, horn and various organs and membranes, and the 
deposits of fat which are quite generally distributed 
throughout the body substance. 

Energy in the forms in which it is used by the ani- 
mal organism may appear as muscular activity, such as 

(151) 



152 . The Feeding of Animals 

working, walking, breathing, the beating of the heart, 
the movements of the stomach and intestines, as heat, 
and as chemical energy necessary for carrying on di- 
gestion and other metabolic changes. The animal body 
is certainly the seat of greatly varied and complex 
constructive and destructive activities, which are sus- 
tained by the matter and potential energy of the food. 
How this is done we do not fully understand, but we 
know many facts which are of great scientific and prac- 
tical importance and which the feeder must consciously 
or unconsciously recognize if he would not come into 
conflict with immutable laws. 



FUNCTIONS OF THE MINERAL COMPOUNDS OF 
THE FOOD 

We have learned that mineral compounds are abun- 
dant in the animal body. The tissues, the blood, di- 
gestive fluids and especially the bony framework con- 
tain a variety of these bodies, which are as essential 
as any other substances to the building and mainte- 
nance of the animal organism. Bone formation with- 
out phosphoric acid and lime is not possible, and to 
deprive the digestive juices of the chlorine and sochi 
which they contain would be to destroy their useful- 
ness. Young animals fail to develop if given no 
mineral food, and mature animals when entirely "de- 
prived of even one substance, common salt, become 
weak, inactive and finally die. Not only must the 
growing calf have the ash compounds for constructive 
purposes, but the mature ox must be supplied with 



Uses of Mineral Compounds — Protein 153 

them in order to sustain the nutritive functions. It is 
especially true of milch cows, which store combinations 
of phosphoric acid, lime and potash so abundantly in 
the milk that they must have an adequate supply of 
these substances. Nothing is clearer than that these 
materials must of necessity be furnished in the food. 
They cannot originate in the animal, neither can car- 
bon compounds take their place. 

Nature seems to have made generous provision 
for the animals' needs along this line. All of our 
home -raised feeding stuffs, as usually fed, contain in 
variet3 r and quantity all that is needful of these nu- 
trients except for poultry perhaps. Milk, that is the 
exclusive food of very young animals, is especially cal- 
culated to sustain the rapid bone formation which is 
taking place. It is only when feeding is one-sided, as 
in an exclusive corn diet, or when parts of a grain are 
removed, that we need fear a deficiency of 'the neces- 
sary mineral compounds. 

FUNCTIONS OF PROTEIN 

While there are at present many unsolved problems 
relative to the nutritive offices of protein, there is no 
reasonable doubt that the vegetable proteids are the 
only sources of similar substances in the animal body. 
This is equivalent to a statement that from the pro- 
teids are formed the muscles, the connective tissues, 
the skin, hair, horn, and hoofs, and the major part of 
the tissues of the secretive and excretive organs; in 
short, that they are the source of a large proportion 



154 The Feeding of Animals 

of all the working parts of the animal's body. So 
far, scientific research has not succeeded in demon- 
strating that an albuminoid is ever synthesized (built 
up from simple compounds) outside of the plant. It 
appears that bodies of this class must come to animal 
life fully elaborated. This is a truth of great sig- 
nificance even in its relation to the nutrition of farm 
animals. The nitrogenous tissues are those that largely 
determine the vigor and quality of any animal, and as 
these are formed rapidly in the early stages of growth, 
a normal and unrestricted development demands an 
abundant supply of proteid food. It is also true of 
mature animals that sufficient protein is not only nec- 
essary to health and vigor, but it is essential to pro- 
duction that is satisfactory in quantity 7 and quality. 

The functions of protein are not restricted, how- 
ever, to the use already described. According to ex- 
isting views, it is utilized in more ways than any 
other class of nutrients. It was held at one time by 
prominent scientists that outside the vegetable fats it 
is the sole source of animal fats, and this view was, 
not so very long ago, to some extent accepted. Indis- 
putable proof to the contrary is now in our possession, 
and some investigators even go so far as to deny the 
possibility of the formation of fat from protein. On 
this point, opinion is divided. Certainly we must be 
convinced that nitrogen compounds of the food are, 
with some species, not the most important source of 
animal fat, for various investigators, such as Lawes 
and Gilbert, Soxhlet, and others, have shown upon the 
basis of searching experiments that sometimes over 



Uses of Carbohydrates 155 

four -fifths of the fat stored by pigs must have had 
its origin outside the food protein and fat. Besides 
all this, the common experience of feeders that foods 
highly non -nitrogenous are often the most efficient for 
fattening purposes is good common -sense evidence that 
fat formation is not greatly dependent upon the pro- 
tein supply. Nevertheless, the possibility of producing 
animal fat from protein is not disproved, and there are 
several considerations which make it seem probable 
that under certain conditions this does occur. 

Protein can unquestionably serve as fuel, or, in other 
words, as a source of energy. The amount so used 
depends much upon the animal fed and the character 
of the ration. In the case of a. dog eating an exclusive 
meat diet or of a fattening animal which receives a 
ration liberally nitrogenous, probably the greater part 
of the protein eaten is not stored but is used as fuel. 
With milch cows or young animals growing vigor- 
ously, a much larger proportion escapes oxidation. 
The fuel value of protein will be discussed later under 
another head. 

FUNCTIONS OF CARBOHYDRATES 

Carbohydrates are usually characterized as the fuel 
portion of the food, or that part which is burned to 
produce the various forms of energy. This conception 
of the function of these bodies is correct in the sense 
that in the case of ruminants they constitute the 
larger part of the fuel, although not the whole of it. 
For instance, in the case of a cow eating daily sixteen 



156 . The Feeding of Animals 

pounds of digestible organic matter, giving thirty 
pounds of milk containing 15 per cent of solids, 
and neither gaining nor losing flesh, not far from 
five pounds of this organic matter would he found 
in the milk and urine, leaving about eleven pounds 
to be used as fuel, about a pound and a half of 
which might be derived from the protein and fat, 
the remainder, or 9.5 pounds, consisting of carbo- 
hydrates. If a fattening steer were eating the same 
amount of the same kind of food and gaining two 
pounds of live weight daily, the body increase and 
urine would contain not over 2.5 pounds of dry 
matter, leaving not less than 13.5 pounds to be oxi- 
dized, of which twelve pounds might consist of car- 
bohydrates and fat, mostly the former. It is clear, 
then, that while other bodies serve as fuel, the carbo- 
hydrates furnish much the larger part of that which 
is needed for this use. 

Contrary to views that held for a time, it is now 
well established that the animal fats may have their 
source in the carbohydrates ; in other words, starch 
and sugar and related bodies may serve the main 
purpose in feeding animals for fattening. In many 
experiments, notably those with swine, the protein 
and fat of the food have fallen far short of ac- 
counting for the fat in the body increase, some- 
times much the greater part of the latter having 
no possible source other than the carbohydrates. A 
practical expression of this general conclusion con- 
cerning the fat -forming function of carbohydrates is 
seen in the well -recognized value of corn meal as a 



Uses of the Fats — Energy 157 

fattening food, a feeding stuff nearly seven -tenths of 
which consists of starch and its allies. Recent experi- 
ments with milch cows leave scarcely any doubt that 
milk fat may also be derived from carbohydrates. 
These more recent views tend to magnify the impor- 
tance of the carbohydrates as nutrients. 

FUNCTIONS OF THE FATS AND OILS 

So far as is at present known, the possible uses of 
the food fats and oils and of the carbohydrates are sim- 
ilar. In other words, both may serve as fuel and both 
may be a source of animal fat. The differences are that 
the supply of carbohydrates is much the larger, and 
the fuel value of a unit weight of fats much the greater. 
Moreover, it seems possible for a vegetable fat to be- 
come deposited in the animal without essential change, 
whereas fat formation from carbohydrates involves 
complex chemical transformations. 

FOOD AS A SOURCE OF ENERGY 

The living animal, either as a whole or in some of 
its parts, is constantly in motion. This means that 
the animal mechanism is ceaselessly performing work. 
Even if the body is apparently quiet, the heart beats, 
pumping blood to all parts of the body, the lungs are 
expanded and contracted, and the stomach and intes- 
tines keep up the movements which are essential to 
digestion. Besides, a living body is the seat of con- 
tinuous, invisible and complex chemical and physical 
changes that, if not work in the common meaning of 



158 The Feeding of Animals 

the term, are its equivalent. Walking, trotting, pull- 
ing, lifting, pumping blood, breathing, masticating, 
digesting and assimilating food represent, then, a great 
variety of operations of those living machines which we 
have named horse, ox, cow and sheep. 

Now work requires the expenditure of energy. The 
projection of a rifle ball through space at the rate of 
two thousand feet per second is work. The ball does 
not move of itself, but is propelled by the application 
of the energy stored in a powerful explosive. Back of 
every one of our great mechanical operations, such as 
pumping, grinding and moving railroad trains, will 
always be found some sort of energy, and what is true 
of machinery made of wood and iron is equally true of 
that made of bone and muscle. The fact that the 
mechanism is alive does not abrogate a single physical 
law, so that the fundamental principles of energy as 
applied to machines are as fully applicable to the activ- 
ities of animal life. 

It is safe to go farther, and say that the animal 
organism does not originate energy. Among the fun- 
damental conceptions upon which all our knowledge 
of chemical and physical laws rests is this, that energy 
and matter are indestructible, and, moreover, that the 
sum total of these in the universe is unchangeable. 
If, then, the horse expends the muscular energy neces- 
sary to draw a load of one ton over ten miles of road, 
the equivalent of this must have been supplied to his 
body from some outside source. He could not create it. 
We know that this is so, and we also know it is con- 
veyed to the animal in the food. 



Forms of Energy 159 

This is a complex, but a fascinating, field of in- 
quiry; one that is now receiving much attention in our 
researches after a more intimate understanding of the 
facts and principles of nutrition. It will be profitable, 
therefore, for us to gain some conception of the knowl- 
edge of this kind, which so far seems to have a practical 
bearing upon our subject. 

It is natural to first ask, What is energy? This is 
a difficult question to answer in a popular way, and 
the physicists' definition would hardly serve our pur- 
pose. All we can do, perhaps, is to illustrate it by 
pointing out some of its manifestations. Let us re- 
sort to an old illustration. Every farmer's boy has 
doubtless seen a blacksmith hammer an iron rod un- 
til it was red hot. The motion of the hammer-head 
descending with great velocity was suddenly arrested 
when it came in contact with the rod. This descent 
of the hammer-head illustrated one form of active 
energy; viz., motion of a mass of matter. When 
the hammer met the iron rod on the anvil, the 
mass motion ceased. Was the energy therefore last? 
Not unless our fundamental conception is wrong, 
and we find that in this case it is not. The physicist 
teaches us that the motion of the hammer-head, a 
mass of matter, was communicated to the smallest par- 
ticles or molecules of the iron rod, and as the vibra- 
tions of the molecule increased in rapidity, the rod 
grew hotter and hotter. Here we have another illustra- 
tion of energy; viz., the motion of the molecule or heat. 

The iron rod might have been heated in another 
way, — by plunging it into burning charcoal. And from 



160 The Feeding of Animals 

whence would the heat energy come in this case ? 
From the combustion of the carbon. Somehow, when 
it is deposited in the plant, there becomes stored in 
this carbon, in a way about which we can only 
theorize, what perhaps we may call the chemical energy 
of the atom, which, when combustion occurs, is changed 
into heat or molecule motion. From these phenomena 
we learn that not only are there several forms of 
energy, but that one form is transferable into another. 
Perhaps another illustration may still further serve 
our purpose. A small dynamo is being run by a pair 
of horses working in a tread power such as is used 
for threshing grain. The horses are constantly climb- 
ing up a moving treadway and thereby communicating 
motion to machinery. This motion is, by the dynamo, 
converted into electricity, which, by passing through 
the carbon film of an incandescent lamp and there 
meeting resistance, is in part, at least, transformed into 
heat. We have, then, in a chain, muscular effort, 
motion of the mass (pulleys, wheels, etc.), electricity 
and* heat, all active energy and all transferable the 
one into the other. This is a fairly good picture of 
what goes on with the horse himself, externally and 
internally, in sustaining life and performing labor for 
his owner. Back of it all, and this is what interests 
us, is the animal's food. As a result of years of 
patient investigation, it has become known that 
through the combustion of the carbon compounds of 
vegetable and animal origin, which serve as nutrients, 
chemical energy may be transformed into those other 
forms that are manifested in the activities of living 



Measurement of Energy 161 

beings. When we ask from whence comes the energy 
given up by the plant compounds, we arrive at our 
last stage of inquiry. Here we enter the domain of 
plant life, and it is a notable triumph of the human 
intellect that we are able to declare with certainty that 
the ceaseless and multiple activities of life on this 
planet are sustained by an energy which comes to the 
plant in the sun's rays through almost limitless space. 
It is obvious that if the internal and external work 
performed by the animal are sustained by the food, it 
is desirable to measure the energy available in differ- 
ent feeding stuffs, provided, of course, that they differ 
in this respect, as we know they do. In order to 
measure anything, we must have a standard or unit of 
measurement. In this case it cannot be a unit of 
space or of mass, that is, we cannot declare that corn 
meal contains so many cubic feet or pounds of avail- 
able energy. Energy has neither dimensions nor weight. 
If we measure it at all, it must be by units of tem- 
perature or of work performed. Units of this kind 
are applied to the measurement of food energy. The 
one most commonly in use is the Calorie, this being 
the energy which in terms of heat is sufficient to raise 
the temperature of one pound of water 4° Fahren- 
heit. Expressed in terms of work, the Calorie is very 
nearly 1.53 foot tons, or in other words, it is equiv- 
alent to the work involved in lifting one ton 1.53 
feet. Heat units are expressed in both the large 
Calorie and the small calorie. When the former is in- 
dicated, the word begins with a capital letter. The 
Calorie represents 1,000 calories. 

K 



162 The Feeding of Animals 

The total energy or heat units developed in the 
combustion of feeding stuffs is determined in an ap- 
paratus called a calorimeter. The latest form of this 
device is one in which the ground hay is burned under 
pressure in the presence of pure oxygen, and the heat 
evolved is all used in warming a known weight of 
water. Data are thus obtained from which it is possi- 
ble to calculate the Calories in the particular material 
burned. The energy value of single compounds, such 
as albumin, starch and sugar, may also be found in 
the same way, as has been done in a large number of 
instances. These data show that the heat resulting from 
the combustion of the compounds of the same class is 
not the same in all cases. The value in large Calories 
of one gram (about one -twenty -eighth of an ounce) 
of the several nutrients is shown in the following table: 

Albuminoids, etc. 

Cal. Cal. 

Wheat gluten 5.99 Egg albumin 5.73 

Gliadin 5.92 Muscle (pure) 5.72 

Glutenin 5.88 Blood fibrin 5.64 

Plant fibrin 5.94 Peptone 5.30 

Serum albumin 5 . 92 Wool 5.51 

Milk casein 5.86 Gelatin 5.27 

Yolk of egg 5.84 Asparagin (amide) 3.45 

Carbohydrates Cal Fats c j 

Starch 4.18 Of swine 9.38 

Cellulose 4.18 Of oxen 9.38 

Glucose 3.74 Of sheep 9.41 

Cane sugar 3.95 Maize oil 9.28 

Milk sugar 3.95 Olive oil 9.47 

Maltose 3.95 Ether extract of oats. . . 8.93 

Zylose 3.74 Ether extract of barley. 9.07 



Available Energy 163 

The heat values of a gram of the dry substance 
of various cattle foods, which is a mixture of the 
several nutrients, was found by recent determinations 
to be the following, expressed in small calories: 

cal. eal. 

Mixed hay 4494 Corn meal 4471 

Alfalfa hay 4478 Linseed meal 5040 

Oat straw 4480 Flaxseed meal 6935 

Sugar beets 3931 Rice meal 4400 

These figures mean that when a gram of each of 
these materials is wholly burned the heat produced is 
as stated. 

Available energy. — We must distinguish, however, 
between the heat produced when any food substance is 
wholly oxidized in a calorimeter and the heat or energy 
which is available when the same material is applied to 
physiological uses. It never happens that the combus- 
tible portion of a ration is entirely burned in the animal. 

In the first place, the food of domestic animals is 
practically never all digested and, as only the digested 
portion furnishes energy, the available fuel value of a 
ration must be based primarily, not upon the total 
quantity of dry matter it represents, but upon the 
amount which is dissolved and passes into the blood. 
If all feeding stuffs or rations were digested in the 
same proportion and with the same ease, their total 
fuel values might show their relative energy worth, but 
as digestion coefficients for dry matter vary from less 
than 50 per cent with the straws to nearly 90 per cent 
with some of the cereal products, it is evident that the 
fuel waste in the feces is not uniform. 



164 The Feeding of Animals 

In the second place, the digested proteids are never 
fully burned. A portion of these compounds always 
passes off in the urine unoxidized, the fuel value of 
which is lost to the animal. For this reason the avail- 
able energy of the proteids is about one -fourth less 
than the total. 

In the third place, there is, with ruminants and 
horses at least, an escape from the alimentary canal 
of unconsumed gases, due to the fermentations which 
take place during digestion. These gases, mostly 
methane (marsh gas), have their source in the carbo- 
hydrates, and Kellner found them to represent from 
10 to 20 per cent of the total energy value of the 
dry substance digested from various materials. From 
twenty experiments, upon five different animals, Kiihn 
found the loss in methane to be over one -seventh the 
energy of the digested crude fiber and nitrogen -free 
extract. 

We are to understand, then, that the available 
energy of a ration is represented by the fuel value of 
the dry matter which is digested from it, minus the 
dry matter of the urine and that lost in gases. 

If, however, we wish to know the actual energy 
gain to the animal from a particular ration, we must 
go farther than a determination of its available energy. 

Net energy. — Within a comparatively short time we 
have begun to speak of the net energy of foods, and as 
this is a practical consideration which is likely to be 
the subject of much future discussion, it is well to no- 
tice it in an explanatory way. As we have learned, 
food is not applied to use until it reaches the blood. 



Energy Loss in Work of Digestion 165 

Between the time when it is taken into the mouth and 
when it passes into the circulation, it must have work 
expended on it in the way of mastication, solution and 
moving it along the digestive tract, and it appears 
highly probable that the amount of this work per 
pound of food must vary greatly in different cases. 
In fact, we know this is so from the result of some 
masterly investigations conducted by Zuntz in Ger- 
many. By means of various devices and methods, a 
description of which would be out of place here, he 
measured the oxygen consumption necessary to sustain 
the mechanical energy of mastication and digestion, 
and he calculates from his determinations that the fol- 
lowing heat units represented the energy used in 
chewing certain feeding stuffs: 

cal. eal. 

1 pound hay 76 1 pound corn 6 % 

1 pound oats 21 Green fodder equal to 1 

pound of hay 47 

The differences revealed by these figures are inter- 
esting and important. Chewing green food cost in 
labor only about 62 per cent of the effort required to 
masticate its equivalent of dry hay, the proportions of 
labor for hay, oats and corn being in the ratio of 
100, 27 and 8%. 

This author goes further and calculates that the 
work of mastication and digestion combined is 48 
per cent of the energy value of the digested mate- 
rial from hay and 19.7 per cent of that from oats. 
He also makes the statement that in general the coarse 
foods have 20 per cent less net energy value than the 



166 . The Feeding of Animals 

grains. All these deductions are based upon the excess 
of oxygen used by the animal when engaged in the work 
of chewing and digestion, over that used when at rest. 
It follows from these results that anything in the way of 
growth or treatment of a fodder which tends to toughen 
or harden the tissue reduces the net energy value. It 
has long been believed, though perhaps not proved, that 
grain foods are superior to coarse foods to an extent not 
accounted for by the differences in digestibility, and if 
this is a fact, it is explained in part by the unlike com- 
position but is to some extent undoubtedly due to the 
greater effort of chewing and digesting the fodders. 

If we wish to ascertain the comparative energy worth 
of two unlike rations, it would obviously be incorrect to 
multiply the total quantities of protein, carbohydrates 
and fats in each by the unit heat values in order to 
ascertain the relative energy gain to the animal body. 

To recapitulate, we may define available energy as 
total energy minus that which is lost in the excreta and 
in gases which escape, and net energy as available energy 
minus the cost of digestion and of preparing the food for 
use. Net energy is the balance of profit to the animal. 

ENERGY RELATIONS OF THE SEVERAL NUTRIENTS 

As has been pointed out, the animal body is the field 
of numerous mechanical activities. What is the rela- 
tion of the several nutrients to these manifestations of 
vital energy is an interesting and in some ways an 
intensely practical matter. For instance, has protein 
a peculiar function in the maintenance of muscular 



Maintenance of Muscular Effort 167 

activity which no other nutrients have f The belief 
prevailed at one time, that muscular contraction caused 
a wasting of the muscle substance which must be re- 
placed by the proteid compounds of the food; in other 
words, protein alone was believed to sustain the work of 
the animal body, both internal and external. It would 
folloAv from this that the more work is done the more 
protein is needed. This view is no longer held. The 
more exact methods of modern research have revealed 
the fact that an increase of muscular effort, even up to a 
severe point, increases but little, if any, the nitrogen 
compounds of the urine, these being the measure of the 
protein that is destroyed. There has come to light a 
corresponding fact that the consumption of fuel in the 
body other than proteids increases proportionately with 
the increase of work. This means that as animals are 
ordinarily fed mechanical work is largeh^ sustained 
through the combustion of carbohydrates and fats, and 
that while for reasons we do not yet wholly understand 
a fairly generous amount of protein seems to promote 
the well-being of a draft animal, the non- nitrogenous 
nutrients mostly supply the extra energy demanded for 
the labor. 

Heat relations. — The question is very naturally 
asked, As no energy is lost, into what is the energy of 
muscular contraction converted, as, for instance, that 
required for walking, the beating of the heart and the 
work of the intestines ? It is concluded by physiologists 
that muscular energy used by the animal is partly trans- 
formed into external motion and partly into heat, and 
this certainly is consistent with facts as observed. Vio- 



168 The Feeding of Animals 

lent exercise by the animal greatly increases the produc- 
tion of heat. We know this is so because under these 
conditions an increased amount of blood is thrown to 
the surface of the body, thereby greatly increasing the 
loss of heat by radiation; perspiration sets in and with 
it the consequent evaporation of much more moisture, 
thus disposing of much heat. The dog, and sometimes 
other animals, pants and thereby causes a large loss of 
heat from the expanded surface of the moist tongue. 
All this occurs without reducing the body temperature 
below the normal. In fact, nature adopts these various 
devices, such as increased circulation of the blood and 
perspiration, in order to regulate the body temperature 
and prevent its rising above the proper point. The 
explanation of this greater heat during labor is that the 
mechanical energy manifested by the muscles is con- 
verted to heat, which under circumstances of severe 
exercise is more than enough to keep the body at its 
usual temperature and maintain the usual radiation. 
When it is severely cold, on the other hand, vigorous 
exercise is sometimes necessary in order to keep suffi- 
ciently warm. 

The view is held by some that all body heat is a 
secondary product, that combustion first supports mus- 
cular activity which changes to heat, in fact, that no 
food is burned primarily to keep the animal warm. 
Convincing proof of this position is still lacking, how- 
ever. There appears to be no good reason why we 
should deny the possibility of combustion of food for 
the specific purpose of warming the body. Certainly 
an Arctic climate causes a consumption of food which 



Heat Re (j illation 169 

in kind and quantity would be impracticable in the 
tropics, and this too, even if there is no apparent in- 
crease of internal or external work. This would seem 
to indicate the direct oxidation of food for heating 
purposes. In any case, animal heat is sustained either 
directly or indirectly by the burning of the nutrients. 



CHAPTER XII 

PHYSIOLOGICAL VALUES OF THE NUTRIENTS 

The preceding discussion of the physiological uses 
of the various nutrients has dealt largely with them 
as classes. The special functions and relative values 
of individual compounds within the same class or of 
the different classes have not been considered. We 
know, for instance, that the albuminoids are in a 
general way flesh -formers, or fat -formers, or heat- 
formers, but we desire still further information as to 
the relative efficiency of the individual albuminoids for 
any specific purpose. Are some albuminoids more use- 
ful than others in aiding milk secretion ? Similar 
knowledge concerning the non-nitrogenous nutrients is 
important. How valuable physiologically is cellulose 
as compared with starch ? 

Again we are convinced that both the carbohy- 
drates and the vegetable fats may be sources of animal 
fats, but we are bound to inquire what is the relative 
importance of these groups of compounds as fat- 
formers in the animal body. 

It is easy to understand that knowledge of this 
kind would be valuable. We are coming to know a 
great deal about the composition of the various cattle 
foods, and if we could ascertain the exact physiologi- 

(170) 



Relative Energy and Production Values 171 

cal uses and relative values of even the most promi- 
nent individual compounds, we would be able to make 
somewhat definite comparisons of the different feeding 
stuffs. It must be confessed that information of this 
specific kind is not as complete as one could wish. 
Its acquirement is very difficult and its present status 
is in some particulars unsatisfactory. Investigations 
so far conducted are not only insufficient to final con- 
clusions, but researches by different observers have re- 
sulted in a conflict of opinion in some cases. 

RELATIVE ENERGY AND PRODUCTION VALUES OF THE 
NUTRIENTS SINGLY AND AS CLASSES 

It is satisfactorily established, as we have seen, 
that protein, carbohydrates and fats have certain func- 
tions in common, that is, that all three classes are 
utilized as fuel, and that both carbohydrates and fats, 
and perhaps protein, may be a source of body fat. 
The question naturally arises, What is the relative 
value of these unlike nutrients as a source of energy 
and as fat-formers? Moreover, as each class is made 
up of a variety of substances, unlike in physical and 
chemical characteristics, can we consider the individual 
compounds within the same class as nutritively equal ? 

Relative energy values.— As a source of energy, the 
carbohydrates and their allies are properly regarded as 
of first, importance because of their large relative use 
as a fuel supply. These bodies, so far as they are 
digestible, have been considered in formulating rations 
as of practically equal value. It is well known that 



172 The Feeding of Animals 

this is a doubtful assumption. The nitrogen-free ex- 
tract digested from the fodders is much more largely 
derived from crude fiber and the gums than that di- 
gested from the grains, starch being predominant in 
the latter, and we are not justified in concluding, 
except from reliable evidence, that the materials from 
the two sources are similar and equivalent as nutrients; 
in fact, some investigators believe the reverse to be 
true. 

If we accept the heat of combustion of the carbo- 
hydrates and similar substances when burned in a cal- 
orimeter as the measure of their energy value, we have 
definite figures. The heats of combustion of the com- 
pounds found in the nitrogen-free extract have been 
found to vary from 3.7 to 4.2 Calories per gram. 
This indicates no great difference in value for the 
production of heat energy. We are not sure, how- 
ever, that what is true of simple, rapid combustion is 
true of physiological use. Certain related facts must 
be considered. Because of Tappeiner's conclusion that 
the fermentations to which cellulose is subject, break 
it up mostly into gases and organic acids which he 
regarded as largely not useful to the animal, the view 
has more or less prevailed that digested crude fiber is 
greatly inferior to starch as a nutrient. More recent 
investigations throw doubt upon the correctness of 
this view, and the trend of opinion now seems to~ be 
towards regarding cellulose as taking practically the 
same place in nutrition, apart from ease of digestion, 
that starch does. It appears that the fermentations 
in the digestive tract of starch, sugar and other carbo- 



Value of the Nutrients 173 

hydrates also give rise to gases which pass off uncon- 
sumed, though perhaps not to the same extent as is 
the case with crude fiber, and several observers de- 
clare that digested crude fiber is no less nutritively 
efficient in a maintenance ration than the more soluble 
compounds of the nitrogen -free extract. 

The question has been raised as to whether the 
gums (pentosans) which exist so abundantly in many 
coarse foods and in some grain products, like wheat 
bran, are not inferior to the other more soluble carbo- 
hydrates. It has been observed that the sugars which 
result from the action of ferments on these bodies 
have, in some instances, not been oxidized, but have 
passed off in the urine as such. It appears doubtful 
whether under normal and usual conditions this occurs 
to any extent. The gums are constantly present in all 
rations for farm animals, and we have no reason for 
believing that the pentose (gum) sugars are constant 
ingredients of their urine. 

The comparative physiological values of individual 
albuminoids and fats we do not know very much about, 
other than what we may judge from the determinations 
of heats of combustion. In experimental work single 
compounds have been but little studied. The conclu- 
sions reached have usually been based upon the results 
of feeding mixtures of individual albuminoids and fats 
as they ordinarily exist in plants. 

Determinations of the heats of combustion of single 
and mixed albuminoids and fats from various sources 
show a variation of from 5.6 to 6 Cal. per gram for 
the former and from 9.2 to 9.6 Cal. for the latter. The 



174 The Feeding of Animals 

variation for the same class is seen not to be large, but 
whether the animal derives energy in similar propor- 
tions must be decided by experimental evidence. 

In recent years much attention has been given ex- 
perimentally to the physiological values of the nutrients. 
Among the most painstaking and extensive investiga- 
tions of this sort are those conducted at Mockern by 
Kellner and his associates. This work includes forty- 
four metabolism experiments, each of fourteen days' 
duration, and one hundred and eighty -four respiration 
experiments, each of twenty -four hours' duration. In 
order to secure the desired data, there was added to a 
basal ration gluten, oil, potato starch, extracted straw 
(mostly cellulose freed from incrusting and accom- 
panying compounds), meadow hay, oat straw, and well- 
ripened wheat straw. From the results obtained, 
through exact measurements of the ingested food, the 
excreta and the products of respiration, — thus making 
it possible to determine the relation of each substance to 
the maintenance of the animal and to the storage of 
flesh and fat, — Kellner worked out both the energy and 
the production values of the experimental materials. 
While the figures given should not be regarded as 
final, they have behind them so much careful and severe 
investigation that they must be accepted as having 
great weight. They at least correctly record what 
happened with particular animals. 

In presenting these results a distinction is made 
between available energj* value and production or net 
value. It is the former which interests us at this point, 
and it is this which is shown in the following figures: 



Available Energy in Typical Nutrients 175 

Total heat value Per cent of Available heat Comparative 

of 1 gram of loss in urine value for 1 gram available heat 

digested and gases- digested value when 

organic matter methane organic matter starch is 100 

cal. Percent cal. 

Starch 4183 10.lt 3760 100 

Extracted straw.. 4247 14. t 3651 97 

Molasses 4075 10.4 3645 97 

Meadow hay 4480 18.7 3640 97 

Oat straw 4513 16.9 3747 100 

Wheat straw 4470 25.6 3327 88 

Gluten 6148 19.3tt 4958 132 

Peanut oil 8821 8821 235 

t Loss wholly from methane. tt Loss wholly in urine. 

The available energy is seen in the total energy of 
the digested organic matter less that which is lost in 
the nrine and from fermentations which produce the 
gas -methane. 

These figures show the energy or heat furnished to 
the animal by the different materials after deducting 
losses. They also represent the heat production when 
the substances were fed in a maintenance ration, 
and as Rubner has demonstrated that the heat lost 
from the animal that is eating just a maintenance 
ration is a measure of the animal's use of food, 
these values show what the different substances were 
worth for maintenance purposes. It appears that 
in these investigations the sugars of molasses, ex- 
tracted cellulose and the material digested from the 
coarse foods containg much cellulose and gums sup- 
plied practically the same available energy to the 
animal that starch did, wheat straw excepted. 

Relative production values of the different nutrients. 
— If we calculate the fat -forming value of protein and 



176 The Feeding of Animals 

starch on a purely theoretical basis as Henneberg did 
some years ago, it would appear that 100 parts of body 
fat can be obtained from 194 parts of albuminoids or 
244 parts of starch. The fat factor of albuminoids 
would be therefore 51.4% and of starch 41%. The 
equivalence of food fat in terms of body fat has never 
been expressed on such a basis, though it is customary 
to assume that the fat of the food may cause the pro- 
duction of an equal quantity of body fat or milk fat, 
an assumption which has no foundation whatever. 

These theoretical figures are an attempt to show 
what protein and starch may do when actually used 
for storage purposes. They cannot be accepted as 
meaning much in indicating how the food is really 
used in practice. It is probable that the excess of 
food over and above maintenance is never all used 
for production according to the theoretical possibilities 
based upon chemical rearrangements of compounds. 
Certainly the production from a given quantity of 
food varies greatly under unlike conditions. It can 
scarcely be doubted that the proportion of the avail- 
able nutrients which are consumed, that is, burned as 
fuel, increases as the ration increases above what is 
needed for maintenance, and inversely the proportion 
of the nutrients stored, in the body as flesh and 
fat is less the greater is the quantity fed in excess 
of the demands for maintenance. A large excess over 
maintenance is relatively less efficient than a small 
one. There comes a point where additional food pro- 
duces no additional gain, but only additional consump- 
tion. The age of the growing animal and the condition 



Productive Value of Typical Nutrients 177 

of a fattening animal also modify the efficiency of the 
food for production purposes, as does the period of lac- 
tation with a cow. With all these variations we have 
no averages which express with any definiteness the 
relative practical production value of the different nu- 
trients. Nevertheless this question has been the sub- 
ject of severe and extended investigation, and some of 
the results have given valuable information. 

Henneberg and Pfeiffer estimate that in experiments 
with sheep the protein in excess of maintenance caused 
the production of from 30.7 to 41.1 parts of fat for 
each 100 parts of protein. It is not shown that the 
fat came directly from the protein or from the carbo- 
hydrates which the excess of protein replaced in other 
uses. Experiments by Kiihn are made the basis of 
the conclusion that 1 pound of starch supported the 
storage of .2 pounds of fat. 

The most reliable and extensive data as to pro- 
ductive values are those already referred to as having 
been reached by Kellner and others at Mockern. They 
are summarized in the following table: 

Heat Mainten- Percentage Productive Compara- 

value anee value Mainten- value tive 

grain grata ance value gram productive 

organic organic applied to organic value, 

matter matter production matter starch 100 

cal. eal. Per cent cal. 

Starch 4183 37G0 58.9 2215 100 

Extracted straw... 4247 3651 63.1 2304 104 

Molasses. 4075 3645 63.6 2310 104 

Meadow hay 4480 3640 41.5 1512 68 

Oat straw 4513 3747 37.6 1409 64 

Wheat straw 4470 3327 17.8 592 27 

Gluten 6148 4958 45.2 2241 101 

Peanut oil .. 8821 8821 56.3 49t!6 224 

L 



178 The Feeding of Animals 

The productive value is stated in terms of the 
available energy less (1) the energy devoted to the 
work of chewing and digestion, and (2) that which is 
appropriated to the molecular rearrangement of the di- 
gested compounds which are transferred to the body 
substance. 

These being the factors which diminish productive 
value, it is easy to understand how the usefulness of a 
nutrient is somewhat determined by its source. When 
it is contained in a coarse fodder like straw where the 
work of chewing aud digestion is large and where, 
because of its physical condition, the fodder is slowly 
acted upon by the digestive fluids and is thus subject 
for a long time to the action of micro-organisms, the 
nutrient is less valuable than when supplied to the ani- 
mal in grain where the work of mastication, digestion 
and solution is a minimum. Starch, extracted straw 
and molasses, requiring no energy for mastication and 
but little for solution, supply digested material which 
Kellner found to be four times as valuable for pro- 
duction as that coming from ripe wheat straw 

The foregoing figures do not tell us how much a 
steer would gain daily when fed upon a certain quantity 
of these nutrients, but they do indicate in a general 
way what is the relative efficiency of the nutrients 
when derived from given sources. They give us a 
scientific explanation of the fact that coarse foods are 
not adapted to rapid production. 

Relative importance of the protein compounds. — 
Much prominence has been given to the fact that 
protein includes several groups of nitrogen compounds 



Differences in Protein Compounds 179 

quite unlike in character. We know also that these 
groups exist in cattle foods in unlike proportions. 
For example, a much larger part of the protein of 
roots consists of amides than is the case with the 
grains, the protein of the latter being correspondingly 
richer in albuminoids. If, therefore, albuminoids and 
amides differ in function or value, we have established 
one point of unlikeness between cornmeal and turnips. 
The testimony so far obtained is quite consistent in 
one direction, and indicates that the flesh -forming 
function is confined to the true albuminoids. This 
means that gelatin, amides (asparagin, etc.), extrac- 
tives (creatin, etc.), cannot supply real muscle-build- 
ing material. These non-proteids have nutritive value, 
however. Experiments with gelatin and asparagin 
have led to the conclusion that their presence in the 
ration so protects the albuminoids from consumption 
that the latter may have their maximum use as flesh- 
and milk -formers. The extractives seem to have a 
peculiar place among the nutrients. They are not 
regarded as flesh -formers, or as fuel, but so far as 
is known they act merely as stimulants of the nervous 
system. 

The albuminoids are the only flesh -formers. There 
are, however, many albuminoids, and they differ among 
themselves as raw material out of which to construct 
the primary tissues of the animal body. Can albu- 
mins do what globulins cannot ? Are nucleins su- 
perior to albumins for special purposes % Not much 
that is definite can be said on this point. Because 
the various nitrogenous feeding stuffs are so generally 



180 The Feeding of Animals 

interchangeable in the ration, without marked effect 
upon its efficiency when the protein supply is not 
diminished, it seems probable that the albuminoids are 
largely interchangeable in use. On the other hand, 
certain observed facts throw doubt on this view. For 
example, well-conducted experiments show that animal 
protein is superior to vegetable protein as food for 
ducks, when the two kinds are supplied in equally 
digestible quantities. It is possible that there are 
other differences in the effect of the protein from un- 
like sources which the ordinary methods of observation 
have not been competent to detect. 

One interesting question which has been consid- 
ered, is whether the special nuclein bodies (albu- 
minoids containing phosphorus) which are found so 
abundantly in eggs and in milk must be supplied as 
such in the food, or whether they may be built up in 
the animal from other albuminoids and phosphates. If 
we could learn that the food must contain these pe- 
culiar albuminoids all ready for use, then we would have 
a valuable suggestion for feeding cows and poultry. 
It now seems improbable that this is the case. The 
sea salmon, which, during its stay up the river, is 
believed to take no food, undoubtedly produces large 
masses of eggs from the body substance, and it seems 
unlikely that so much nuclein as is needed exists in 
the flesh. If a cow gives thirty pounds of milk daily, 
nearly or quite a pound of casein must come from 
somewhere, and there is no evidence that any ordinary 
ration would contain so large a quantity of phosphorized 
albuminoids. Hens' eggs are rich in nuclein, bej^ond 



Differences in Protein Compounds 181 

any amount which the food seems likely to supply. 
Notwithstanding this indirect evidence, it cannot be 
safely affirmed that one albuminoid does not pos- 
sess much greater value for a specific purpose than 
another, and here is a field in which the investigator 
may render valuable service. 



CHAPTER XIII 

LAWS OF NUTRITION 

The preceding pages have been devoted to a discus- 
sion of the origin of cattle foods, what they are in 
substance, how their nutrients are made available and 
how used. So far no attempt has been made to 
gather together in a systematic relation what may be 
called the fundamental principles or laws of nutrition, 
some of which we have not yet directly stated, but 
which are inferences from the facts presented. It is 
desirable to do this, however, before passing to the 
consideration of the practice of cattle feeding. 

1. All energy and building material applied to the 
maintenance and growth of the animal body come 
from the food, water and oxygen being included in 
this term. The animal originates neither force nor 
matter. 

2. Only that portion of the food which is digested, 
i. e., that which is dissolved by the digestive fluids 
and rendered soluble and diffusible so that it passes 
into the blood, is available for any use whatever. This 
facu is especially important in view of the greatly 
varying digestibility of different feeding stuffs. 

3. The unutilized food and the wastes pass from the 
body in some direction. The undigested part mainly 

(182) 



Laws of Nutrition 183 

constitutes the solid excrement or feces. The urea and 
other nitrogenous compounds which are the unoxidized 
portion of the protein, pass out wholly in the urine. All 
digested nitrogen not stored is found here. The car- 
bon dioxid is eliminated through the skin and lungs, 
chiefly the latter, and water is disposed of through 
the kidneys, skin and lungs. 

4. The digested food is used in two general direc- 
tions, (a) for the protection of energy and (6) for 
constructive purposes. 

(a) The food energy is made available through 
combustion, i. e., the burning of the carbon compounds 
of the food to simpler substances, carbon dioxid and 
water, thus liberating the energy stored in the plant 
during its growth. Protein is never fully oxidized, but 
carbohydrates and fats may be. All the organic nu- 
trients may be oxidized to produce energy, the total heat 
values of protein, carbohydrates and fats being approx- 
imately as 1.5, 1, 2.4. This liberated energy finds ex- 
pression in the animal organism in various ways, as heat, 
mechanical energy or motion and chemical transforma- 
tions. The total energy of food is never all available to 
the animal because of a loss in the excreta and gases. 
Moreover, the net energy gain seems not to be propor- 
tional to the available energy, but is dependent upon the 
work of digestion, which varies with different cattle foods. 

(b). The food compounds are used for constructive 
purposes, either without changing their general char- 
acter, as, for instance, the building of muscular tissue 
from the plant albuminoids, or they may be reorgan- 
ized into bodies of a very different character, as in the 



184 The Feeding of Animals 

formation of animal fats from starch and sugar. Pro- 
tein is used to construct muscular tissue, in fact, all 
the nitrogenous parts, and it is perhaps a source of 
fat. Carbohydrates can only be used constructively 
for the formation of fat, and the same is true of food 
fats or oils. Mineral matter is needed for the forma- 
tion of bone and has important functions in digestion. 

5. The matter of the digested food, including water 
and oxygen, is exactly equal to that stored in the body 
or in milk, or both, plus that in waste products, — feces, 
water, carbonic acid and urine solids. Such a balance 
may not be maintained for any particular day, but will 
ultimately be found to exist. 

6. Under given conditions of species, sex, climate 
and use, a definite amount of digested organic matter 
is necessary to maintain a particular animal without 
gain or loss of body substance. This means simply 
that tissue wastes must be replaced, and the fuel sup- 
ply must be kept up. 

If the animal receives no food, or less than the 
amount needed for maintenance purposes, tissue waste 
and the production of energy do not cease, but go 
on wholly or in part at the expense of the body sub- 
stance, and, as it is commonly expressed, the animal 
"grows thin." 

7. Food supplied above a needed maintenance quan- 
tity may be utilized for the production of new sub- 
stances or work or may be eliminated in part and increase 
the waste. Within limits, both things generally occur. 
In the proper sense of the term, no production ever 
occurs without an excess of food above the mainte- 



Laws of Nutrition 185 

nance requirement. Milk formation may sometimes 
go on at the expense of the body substance, but with 
proper feeding, milk, flesh or muscular work are pro- 
duced at the expense of food supplied in excess of that 
needed for maintenance. 

8. Regard must be had to the supply of particular 
nutrients as well as of total food. Even with an ani- 
mal doing no work and giving no milk a certain 
amount of protein will be broken up constantly into 
urea and similar compounds, an amount which will be 
withdrawn from the body tissues to the extent that it 
is not supplied by the food. In addition to this, a milch 
cow, for instance, must have protein for the formation 
of the nitrogen compounds of the milk, or a steer for 
the growth of flesh in a quantity proportional to the 
production, and food must supply it. There is, there- 
fore, a minimum supply of protein, which, in a par- 
ticular case, is necessary for maintenance and for 
constructive purposes, less than which ultimately dimin- 
ishes production to the extent of the deficiency, or else 
requires the use of body tissue. . 

9. The different classes of nutrients are to some 
extent interchangeable in their functions. That is to 
say, all the organic nutrients may be burned to supply 
energy. Protein may be so used even to withdrawing 
it from the purposes to which it is necessary unless 
the carbohydrates or fats are sufficient to protect it from 
being consumed as fuel. A proper supply of the non- 
nitrogenous nutrients is required, therefore, to insure 
the application of the necessary minimum of food pro- 
tein to its peculiar uses. 



CHAPTER XIV 

SOURCES OF KNOWLEDGE 

The foregoing chapters embody many statements of 
principles and facts which have been made positively 
and without modification. To quite an extent these 
are based upon the conclusions of scientific men, that 
is, conclusions which have been reached after such study 
of the problems involved as is competent to secure ac- 
curate information. In some cases this study has been 
severe and long continued, having been carried on 
by the use of methods and apparatus capable of the 
most precise measurements. Moreover, in the investi- 
gations of science an effort has been made to pro- 
ceed logically, so that the results attained shall not 
be fallacious. Notwithstanding the fact that a great 
deal of our knowledge is the result of an earnest arid 
impartial search after truth, under conditions espe- 
cially favorable to its discovery, many persons are 
disposed to give more credit to the traditions and 
conclusions of practice than to the carefully prepared 
verdicts of science. It may not be out of place, 
therefore, to present in this connection some of the 
considerations and methods which have to do with 
the acquisition of knowledge concerning animal nutri- 
tion, for this may aid us to appreciate the value of 

(186) 



Real Value of Practical Observations 187 

"well - established facts and to exercise caution in ac- 
cepting the verdicts either of science or of practice 
before they are thoroughly justified. 

There are three general ways in which we may be 
said to have acquired knowledge in regard to feed- 
ing animals: 

1. The observation of ordinary practice. 

2. Practical experiments, so called. 

3. Scientific investigation. 

CONCLUSIONS OF PRACTICE 

Until within recent years, the practice of cattle- 
feeding has been entirely governed by the conclu- 
sions drawn from ordinary practice. Among the many 
men engaged in animal husbandry, certain ones pos- 
sessed of more than average powers of observation 
and business ability have secured good results with 
certain feeding stuffs and methods of feeding, and 
their practice has been accepted by their neighbors 
with no further demonstration than that these success- 
ful farmers sold fat cattle and obtained large returns 
from the dairy. During the centuries that man has 
had domestic animals under his care, certain results 
have appeared to follow from certain systems of feed- 
ing or the use of certain foods, and upon these so- 
called practical observations the feeder has built his 
creed. 

In these ways there have come to be accepted, 
sometimes locally and sometimes generally, standards 
of feeding as to quantity, kind of ration, and times 



188 The Feeding of Animals 

of feeding. At the same time, it was necessary only to 
attend a farmers' convention fifty years ago to become 
convinced of a great variety of opinions as to the best 
methods of practice. In fact, opinion was the court 
of last resort. There were then no known, well-estab- 
lished fundamentals to which appeal could be made as 
a basis for discussion. While many false notions were 
entertained, many of the beliefs then prevailing were 
undoubtedly correct or contained a germ of truth. It 
is generally safe to assume that when an opinion is 
widely and persistently held it is not altogether with- 
out reason or foundation. It is often the expression, 
in more or less correct terms, of some important prin- 
ciple. No one should lightly turn aside from the 
traditions and convictions of a community in regard 
to any line of practice. A knowledge of the precepts 
governing the feeder's art that are the accumulation 
of experience in the care of animals is to be respected 
and is, to a great extent, essential to successful prac- 
tice. It is also true that little substantial progress 
can be realized in any art if its underlying truths are 
not understood, for when this is the case the results 
of experience under one set of conditions do not serve 
as a guide under circumstances entirely different. 

PRACTICAL FEEDING EXPERIMENTS 

With the advent of modern science and of the 
efforts to utilize it in agriculture, an attempt has been 
made to search for important truths more systematically, 
an effort undertaken chiefly by experiment stations. As 



Insufficiency of Some Experiments 189 

one means of gaining knowledge, these institutions, 
and to some extent private farmers, have conducted 
many so-called practical feeding experiments in order 
to verify present beliefs, test theories and solve exist- 
ing problems. The relative value of various feeding 
stuffs and rations for producing growth and milk and 
the influence of different fodders and grain foods upon 
the quality of the product have been the subjects of 
numerous feeding tests. Much valuable information 
has been secured in this way, but there has not 
always been a full recognition, even by experiment 
stations, of the limitations which should be observed 
in drawing conclusions from this manner of experi- 
mentation. 

In order to view this matter more in detail, let us 
consider experiments in testing rations for growth and 
milk production. The usual method of procedure with 
such feeding trials is either to feed two lots of animals 
on the rations to be compared and note the comparative 
growth or milk yield, or to feed the same lot on one 
ration for a time and then change to another ration. 

If these tests are made with growing or fattening 
animals, the increase in live weight is taken as the 
measure of the relative efficiency of the rations com- 
pared. It should be said of these experiments that 
their apparent verdict is to be accepted with great 
caution, and definite conclusions are not justified until 
repeated trials of two rations or of two systems of 
feeding, made with the use of all possible precautions 
against error, and under a variety of conditions, give 
uniform and consistent results in the same direction. 



190 The Feeding of Animals 

There are several reasons why this is so, the main one 
being that the increase in the weight of an animal is an 
uncertain measure of actual growth. Variations in the 
contents of the alimentary canal due to the irregular- 
ity of fecal discharge and to a lack of uniformity in 
the water drank may cause temporary variations in the 
live weight of considerable magnitude. Moreover, the 
nature of the growth of body substance is revealed by 
neither the mere weighing of an animal nor by his 
general appearance. Even if the changes in weight are 
due to an increase of body tissue, this may be more 
largely water in one case than in another,, so that the 
real contribution of the food to the dry substance of 
the body may not be shown. Nor is the character of 
the solids deposited in the animal discovered by merely 
weighing him. In fact, by such practical experiments 
we simply learn that one set of animals has gained 
more or less pounds of weight than another set, but 
the why and the how are not explained. 

Practically the same considerations pertain to feed- 
ing tests for milk production. When the milk flow 
from one ration is larger than from another, we can 
easily satisfy ourselves as to the comparative yield of 
milk solids, which is the real test of such production; 
but we are not able to decide whether the cow either 
may not have contributed to the milk secretion from 
the substance of her own body, or may not have gained 
in body substance, the extent of such loss or gain 
being greater, perhaps, with one ration than with 
another. 

Even if these uncertainties did not exist, we have 



Development of Necessary Knowledge 191 

the still greater disadvantage of not learning by this 
means why a particular combination of feeds has 
superior qualities for causing growth or sustaining 
milk secretion. The mere data showing that an ani- 
mal ate so many pounds of food and produced so 
ruany pounds of beef or milk are important business 
facts, but they reveal nothing concerning the uses of 
the several classes of nutrients and of themselves fur- 
nish slight basis for developing a rational system of 
feeding. We must somehow learn the function of pro- 
tein, carbohydrates aud fats in maintaining the various 
classes of animals and the real effect of varying the 
source, quantity and relative proportions of these nutri- 
ents before we can draw safe general conclusions. 

CHEMICAL AND PHYSIOLOGICAL STUDIES 

As preliminary to more comprehensive and convinc- 
ing methods of investigating feeding problems, there 
has been going on during many years a necessary study 
of the compounds which are found in plants and ani- 
mals. Much has been learned about the ultimate com- 
position aud the constitution of the albuminoids, carbo- 
hydrates and fats, their physical and chemical proper- 
ties, the compounds into which these bodies break 
under certain conditions, the chemical changes to 
which they are subject through certain agencies, and 
their relation to one another. Investigations along 
these lines have for years occupied the time of some 
of our ablest scientists, and, while such researches when 
they were conducted may have seemed to the extreme 



192 The Feeding of Animals 

utilitarian to be of little value, we now see how di- 
rectly they are contributing to human progress and 
welfare. 

To the above information has been added through 
physiological investigations a knowledge of the ways 
in which the several food compounds are transformed 
in digestion and in other metabolic changes, the 
avenues along which these compounds travel, and the 
ways in which their products of decomposition are dis- 
charged from the animal organism. We have learned 
how to distinguish between the digested and undi- 
gested food, have demonstrated that all the nitrogen 
of the decomposed proteids passes off in the urine, 
have measured the combustion of the nutrients and 
have learned how to strike a balance between the in- 
come and outgo of the animal body. It is now possi- 
ble to determine with reasonable accuracy just how 
much substance is retained or lost from the body of 
the experimental animal while eating a given ration, and 
what is the nature of the gain or loss. Very recently 
means have also been devised for measuring the heat 
given off by a man or an animal in order to ascertain 
the actual physiological values of different feeding 
stuffs. 

MORE ACCURATE METHODS OF INVESTIGATION 

In applying the principles and facts of chemistry 
and physiology, the first advance from the ultra -prac- 
tical feeding experiment in the direction of an accurate 
history of what occurs when the animal is eating a 



Progress in Experimental Methods 193 

particular ration is the measurement of the digested 
nutrients and the determination of the gain or loss of 
nitrogen. This is accomplished, as heretofore stated, by 
ascertaining the quantity of various compounds eaten 
and the amount of the same in the feces, the differ- 
ence being the digested portion. The urine is also 
collected, and if the nitrogen in it is less or more 
than that in the digested protein, then the animal is 
either gaining or losing nitrogenous body substance, 
unless the measurement is with a milch cow, when the 
nitrogen in the milk must be taken into account. By 
an experiment conducted in this way, with careful and 
continued weighings of the experimental animal, it is 
possible to secure a probable relation between a unit 
of digested dry matter and a unit of production. Such 
a method has been used to determine what is a main- 
tenance ration for animals of several classes, and in 
those cases where the experiments have been continued 
for a sufficient length of time and have shown on 
repetition a reasonable agreement, we are justified in 
accepting the results as a close approximation to fact. 
When a ration keeps an animal in nitrogen equilibrium 
for one or more months and no material gain or loss 
of weight occurs, we may safely regard it as approxi- 
mately a maintenance ration under the conditions in- 
volved. Experiments of the same kind are equally 
useful in testing the productive power of various food 
combinations, and whenever by such continued tests 
one ration shows no superiority over another, it is 
safe to assume that no differences exist which would 
be especially important to the farmer's pocketbook. 

M 



194 The Feeding of Animals 

RELATION OF FOOD TO PRODUCTION 

Another class of experiments somewhat more severe 
in their requirements are those designed to give infor- 
mation as to the relation between the constituents of 
the food and the growth of the various tissues in the 
animal body or the formation of milk solids. The ex- 
periments conducted by Lawes and Gilbert on the for- 
mation of fat with swine may be cited in illustration of 
the methods used. These were planned so as to learn 
the amounts of digested protein, carbohydrates and 
fat consumed by the animal and also the quantities of 
protein and fat stored in the body during a given 
period. "In experiment No. 1, two pigs of the same 
litter, of almost exactly equal weight, and, so far as 
could be judged of similar character, were selected." 
One was killed at once and its composition determined, 
and the other was fed for ten weeks on a fattening 
ration of known composition and then slaughtered and 
analyzed. The quantity of protein and fat which the 
pig's body had gained during the ten weeks as ascer- 
tained from the composition and weight of the two 
pigs was then compared with the food supply of simi- 
lar compounds. It was assumed that a pound of food 
fat could produce a pound of body fat and that 51.4 
per cent of all the protein not stored in the body 
as such could be used for fat formation. Even with 
the most liberal allowances it was found that the pro- 
tein and fat of the food could not possibly have been 
the sole source of the new body fat, thus forcing the 
conclusion that the carbohydrates are fat -formers. 



Experiments on Use of Nutrients 195 

Practically the same plan has been followed in study- 
ing the source of milk fat. Several cows were fed on 
carefully weighed and analyzed rations extremely poor 
in fat, and the amount and composition of the feces, 
urine and milk were ascertained during sixty to ninety 
days. The fat digested from the food and the theo- 
retical fat equivalent of the decomposed protein as 
measured by the urine nitrogen were charged up 
against the milk fat, and a large quantity of the lat- 
ter could be accounted for only as having had its 
source in carbohydrates. 

Another method of investigating fat formation has 
been used with dogs. It is well known that when an 
animal is deprived of food the expenditure of energy 
by the body is maintained at the expense of body sub- 
stance. Both muscular tissues and fatty substance are 
broken down and used in this way, the latter beiug 
regarded as furnishing the most natural and available 
supply of fuel. It was found in the case of dogs that 
after a certain number of days of starvation there oc- 
curred a sudden and large increase in the waste of 
nitrogen compounds as shown by the urine excretion, 
the explanation for this being that the body fat had 
become exhausted and a demand was at once made upon 
the proteid tissues for the necessary supply of energy. 
As soon as this rise of nitrogen waste appeared, then the 
dog was allowed to eat, and whatever fat was found in 
the body at the end of the feeding period was regarded 
as having been formed from the food taken after the 
starvation period. If, for instance, the ration was 
wholly protein and fat was found to have become de- 



196 The Feeding of Animals 

posited in the body, this was regarded as proof of the 
formation of fat from protein. Such experiments as 
these have not always been conclusive, although they 
are regarded by some scientists as haviug furnished 
proof that protein may be a source of fat. 

THE RESPIRATION APPARATUS 

After all, the investigations of the kinds described 
fail to furnish data so accurate and so complete as are 
necessary for entirely safe conclusions. In every in- 
stance, one or more assumptions are involved where 
definite proof is not furnished. Nothing short of a 
complete record of the income and outgo of the ani- 
mal organism during the experimental period is con- 
clusive evidence as to whether there has been a gain 
or loss of body substance and what is the kind and 
extent of the growth or waste. The securing of such 
a record is an expensive and laborious task. It re- 
quires not only complete information in regard to the 
quantity and composition of the food, but also an ac- 
curate measurement of the excreta, including the feces, 
the urine, the respiratory products and the matter 
given off through the skin. Such measurements are 
taken by means of a respiration apparatus, a costly 
and complicated mechanism, a detailed description, of 
which would be of little use to most readers. It is 
sufficient to state that this apparatus makes possible 
the collection and analysis of all the excretory products,, 
whether solid or gaseous. The experimental man or 
animal lives in a closed chamber into which is intro- 



Investigation with Respiration Apparatus 197 

duced food and fresh air and from which is pumped 
the vitiated air, the water and carbon dioxid of which 
are absorbed and weighed. 

All conclusions drawn from experiments with the 
respiration apparatus are based largely upon the in- 
come and outgo of nitrogen and carbon. As carbon 
is a constituent of all possible compounds of the ani- 
mal body except the mineral, it is certain that when 
the body gains in carbon it gains in organic sub- 
stance of some kind, and if it loses in carbon there 
is a waste of organic body substance. The general 
character of the gain or loss can be determined by the 
nitrogen balance. If more nitrogen is taken in by the 
experimental animal than is given off, it is clear that 
the nitrogen compounds of the body have received an 
accession. Knowing as we do the proportions of nitro- 
gen and carbon in the various tissues of the animal, 
we can calculate how much of the gain or loss of 
carbon belongs in the nitrogenous substance deposited 
or wasted. If more carbon is gained or lost than can 
possibly be associated with the nitrogen gained or lost, 
then there has been a gain or loss of fat, because protein 
and fat being the main constituents of the animal car- 
cass, any considerable retention of carbon must be in one 
of these forms. If there has been nitrogen equilibrium, 
all excess or deficit of carbon belongs to a deposit or 
waste of fat. By such searching methods as these, it 
is possible to ascertain with a good degree of accuracy 
how food is used and what quantity and kind of nu- 
trients are needed in maintaining an animal under 
given conditions. 



198 The Feeding of Animals 

DETERMINATION OF ENERGY VALUES 

We have reached a point in our study of animal 
nutrition where we realize that food values are to 
some extent commensurable with energy values and 
that it is desirable to know the energy product of 
different compounds and feeding stuffs. Moreover, we 
cannot possess sufficiently full knowledge concerning 
the energy needs of the several classes of animals 
until we have measured energy consumption under 
the various conditions of work and of production. 
The mere determination of the income and outgo of 
the animal body does not necessarily measure energy 
needs or use. We may go so far as to ascertain that 
a certain amount of carbon from a certain source 
was consumed in a given time, but from this alone we 
do not learn the extent to which this combustion has 
supported the internal and external work of the body. 

Calculation of the energy value of a ration. — Three 
methods may be adopted for determining the energy 
expenditure by an animal eating a given ration. The 
one of these most easily carried out is largely a 
matter of mathematical calculation. By the use of 
average digestion coefficients it is possible to ascer- 
tain approximately the amounts of digestible protein, 
carbohydrates and fats contained in any ration which 
is apparently accomplishing a desired result. We know 
from previous determinations what are the calorific 
values of individual compounds such as albumin, 
starch, sugar, stearin and olein, and these compounds 
are assumed to represent the energy value of the 



Establishing Energy Values 199 

classes of nutrients to which they belong. If, then, 
we multiply the calculated quantities of digestible pro- 
tein, carbohydrates and fats by their respective as- 
sumed energy factors, we get a number which may be 
taken as an expression of the available energy of the 
ration under consideration. This method cannot be 
regarded as entirely accurate, because the calorific value 
for protein may not be the same as that for any single 
albuminoid, and the heat units of the nitrogen-free 
extract are likely to vary materially from those found 
for the starches and sugars, while the ether extract is 
very far from representing the pure fats. At the same 
,time, it is possible in this way to learn the energy 
value of a ration closely enough, perhaps, for all prac- 
tical purposes. 

Energy value of digested nutrients. — A second 
method, which is probably a step in the direction 
of greater accuracy, is to determine by the use of 
a calorimeter the heat units of the ration and also 
of the urine and feces. The differences between the 
food heat units and those found for the excreta are 
assumed to represent the energy value of that por- 
tion of the ration appropriated by the animal. Pro- 
vided the heat units obtained in calorimeter combus- 
tion and physiological combustion are equivalent, this 
method must be considered as furnishing a reliable 
energy measurement. However probable this equivalence 
may seem, it has not been fully demonstrated. We 
still need more complete experimental proof that the 
oxidation of the several food compounds in ordinary 
combustion and in the animal produces identical re- 



200 The Feeding of Animals 

suits in the two cases. Even if this method gives 
us a correct estimation of the energy equivalent of 
the food used, it furnishes no definite information as 
to the manner of use. It does not appear to what ex- 
tent the digested nutrients have been oxidized with a 
corresponding radiation of heat or whether there has 
been a gain or loss of body substance. If there has 
been a gain of body substance, then the needs of the 
work horse or milch cow, if these are under considera- 
tion, are less than the heat units of the ration, but if 
there has been a loss of body substance, then the 
ration is below the required standard for the par- 
ticular animalr under investigation. In a study of 
energy relations, it is therefore even more necessary to 
resort to a respiration apparatus of some sort than in 
determining food balances. We must learn the actual 
extent of the food combustion which occurs if we 
would have all the data necessary for measuring energy 
used, and here we come to the third and most accu- 
rate method of determining energy expenditure; viz., 
experiments with a respiration apparatus. 

Measurement of food combustion. — There are two 
general ways of ascertaining the extent to which 
food is burned by any living organism. One is to 
measure the products of combustion and the other 
is to measure the amount of oxygen used. It is self- 
evident that no combustion can occur without the 
use of oxygen, and so if the experimenter is able to 
learn just how much of this element is taken up in 
uniting with the carbon and hydrogen of the food, he 
has a direct and accurate means of measuring actual 



Respiration Calorimeter 201 

energy production. The older forms of respiration ap- 
paratuses simpty allowed an estimation of the carbon 
dioxid and water given off by the animal. How much 
of the water was formed by the oxidation of the 
hydrogen of the food and how much was simply evapo- 
rated from the store taken in as water, it was impos- 
sible to know by direct determination. This could 
only be calculated. The carbon dioxid was, on the 
other hand, a direct and accurate measure of the com- 
bustion of carbon. Later devices, as, for instance, the 
one used by Zuntz, allow a direct determination, not 
only of the products of combustion, but of the oxygen 
absorbed by breathing. This method of work has 
great advantages, as one measurement not only checks 
the other, but makes it possible to ascertain the actual 
oxygen consumption during any given period of the 
experiment, as, for instance, when the animal is at 
rest, when masticating food, or when performing a 
given amount of external work. In this way, Zuntz 
made his masterly demonstrations of the differences 
in the net values of different foods due to the greater 
energy cost of masticating and digesting certain ones. 
Respiration calorimeter . — None of the older appara- 
tuses, whether allowing the determination of oxjgen 
consumption or not, measured the heat radiation from 
the animal body, or, in other words, the amount of 
energy actually evolved from internal combustion. 
Recently Professors Atwater and Rosa have devised a 
respiration apparatus which is at the same time a cal- 
orimeter. The quantity of heat radiated from a man 
or other animal confined in this calorimeter is absorbed 



202 The Feeding of Animals 

by a known volume of water and is thus determined. 
This is a great advance towards certainty, because 
direct measurements of the energy of a ration in use 
are thus made possible and the necessity for theoreti- 
cal assumptions is largely removed. 

It is already made clear to the reader, doubtless, 
that the demonstration of facts and principles in the 
domain of animal nutrition is exceedingly difficult. It 
should be equally clear that when conclusions are 
reached in ways which have been briefly described, 
they are worthy of respect and should have greater 
weight than the necessarily imperfect observations of 
common practice. Science often errs in her deduc- 
tions, but the efforts of her workers are constantly 
directed towards the elimination of false conclusions, 
so that unsound theories are not likely to be accepted 
for a great length of time. 



PART II— THE PRACTICE OF FEEDING 

CHAPTER XV 

CATTLE FOODS — NATURAL PRODUCTS 

The number of cattle foods now available for use 
is very large, and the list appears to be constantly 
increasing. Not only have several fodder plants been 
added to those formerly grown, but we have now a great 
variety of waste products from the manufacture of oils, 
starch, and human foods that are being placed upon 
the market as feeding stuffs. At one time farmers 
produced all their cattle ate, and this was done without 
going outside a very limited list of forage plants and 
grains. All this is changed, especially in the older, 
more thickly -settled portions of the United States, so 
that considerable knowledge is now needed regarding 
the composition and specific characters of the numerous 
kinds of feeding stuffs if they are to be used intel- 
ligently. 

It will aid in discussing this branch of our subject 
if we first note the divisions into which the materials 
used for feeding farm animals are grouped. There is 
more than one basis upon which it is possible to make 
these divisions, — botanical relations, the portion of the 
plant used, whether stem or fruit, and chemical com- 
position. As a matter of fact, all these and other 

(203) 



204 • The Feeding of Animals 

distinctions are involved in the classification of the 
cattle foods in common use at the present time. 

The feeding stuffs of vegetable origin are generally 
divided into four classes: (1) forage crops, consisting 
of the stem and leaves of herbaceous plants, either in 
green or air -dry condition, to which is attached in some 
cases the partially formed or wholly mature seed or 
grain; (2) roots and tubers, or the thickened under- 
ground portions of certain plants; (3) seeds or grains; 
(4) parts of seeds or grains which are the by- products 
from the removal of other parts by some manufacturing 
process. These are the commercial by-product feeding 
stuffs. 

FORAGE CROPS 

The valuable forage plants of the United States 
belong mostly to two families, the grasses (graminese) 
and the legumes (leguminosae) . June grass, red top, 
timothy and the cereal grain plants are types of the 
former; and the clovers, alfalfa (Fig. 3), the vetches, 
and peas, of the latter. Whether in the pasture or in 
tilled fields, few plants outside of these divisions con- 
tribute materially to the supply of high -class fodders. 
The most essential difference between the members of 
these two families of plants when considered as feeding 
stuffs is the larger proportion of nitrogen compounds 
in the legumes. It is characteristic of all legumes that 
their proportion of protein is high as compared with 
any other forage crops, and for this reason they are 
greatly prized on dairy farms. The fact that they are 
regarded as increasing materially the nitrogen supply 



Influence of Drying Fodders 



205 



of the farm from sources outside the soil also adds 
to their value. 

Green vs. dried fodders. — Conditions of drying. — 
Nearly all of the herbaceous plants that are grown for 
consumption by farm animals may be fed either in a 
green or dry state. Oats, maize, clover, alfalfa, and 
other species which serve so useful a purpose as soil- 
ing crops for summer feeding are also dried that they 
may be successfully stored for winter feeding, though 




Fig. 3. Crop of alfalfa, New York State Experiment Station. 

maize, and, to some extent, other crops, are now pre- 
served in a green condition through the process of 
ensilage. 

The advantages and disadvantages of green as com- 
pared with dry fodders have been much discussed, and 
some of the facts, chemical and otherwise, bearing 
upon the question are presented in this connection. It 
is safe to assert that the compounds of a dried fodder 
which has suffered no fermentation are practically what 
they were in the green, freshly-cut material, excepting 
that nearly all of the water contained in the green 



206 The Feeding of Animals 

tissues has evaporated and that in drying there is a 
possible loss of an imperceptible amount of volatile 
compounds, whose presence in the plant affects its 
flavor more or less. It is certain that curing a plant 
generally diminishes its palatableness and increases its 
toughness, or its resistance to mastication, although 
with many crops, as for instance the early -cut native 
grasses, these changes do not affect nutritive value to 
a material extent. There is no question but that the 
mere matter of being green or being dry has very little 
influence upon the heat which a fodder will develop 
when burned or upon the extent to which it will 
sustain growth or milk formation. We must, how- 
ever, take into account the desirability of the highest 
state of palatableness. 

It is a fact that drying fodders under perfect con- 
ditions is often not possible. The long -continued and 
slow curing of grass in cloudy weather, especially when 
there is more or less rainfall, is accompanied by fer- 
mentations that result in a loss of diy substance 
more or less extensive, and which involve some of 
the most valuable compounds, principally the sugars. 
The tissues of certain plants, maize for instance, are 
so thick that rapid curing in the field is never pos- 
sible, and fermentative changes are unavoidable. It is 
probable that maize fodder and stover are never field- 
dried without a material loss in food value, for the 
chemist finds that even when the stalks are finely 
chopped, drying by artificial heat is necessary to a 
complete retention of the dry matter. The extent of 
the loss from curing fodders must be very variable. 



Conditions of Curing Fodder 207 

So far as we know, grass, which in "good haying 
weather" is well stirred during the day and packed 
into cocks over night so as to avoid the action of 
heavy dew, suffers practically no deterioration, while 
dull weather or rain may cause a serious loss. It is 
doubtful, however, whether night exposure during good 
weather is sufficiently injurious to justify the expense 
of cocking partially cured hay. On the other hand, 
the economy of using hay caps during unfavorable 
weather is without question. The over -drying of hay 
before raking into winrows and "bunching" so as to 
cause a loss of the leaves and the finer parts through 
brittleness may be as wasteful as under -drying and 
the consequent fermentation. Over -dried hay does 
not pack well in the mow and is less palatable. The 
leguminous hays, such as clover and alfalfa, are es- 
pecially subject to loss from over -drying before han- 
dling. Fodder crops, if dried at all, should be dried 
to such a per cent of moisture that they will not 
"heat" to discoloration after being packed in large 
masses and lose dry matter from the same general 
causes that operate in field - curing under bad con- 
ditions. 

The harvesting of forage crops. — The result to be 
achieved in the growing of forage crops is the produc- 
tion on a given area of the maximum quantity of di- 
gestible food materials in a palatable form. The age 
or period of growth at which a forage crop is harvested 
is an important factor in this relation and may affect 
the product in three ways: (1) in the quantity of ma- 
terial harvested, (2) in the composition of the crop, 



208 The Feeding of Animals 

and (3) in the palatableness of the resulting fodder. 
In discussing this question we must recognize the fact, 
first of all, that in these respects no general conclusion 
is applicable to all crops. What would be wisest in 
the management of the meadow grasses might be 
wasteful in handling the legumes, and especially so in 
harvesting maize. 

The truth of this statement will appear as the facts 
are displayed. 

It is safe to assert that in general the maximum 
quantity of dry matter is secured when forage crops 
are allowed to fully mature and ripen. The only 
exception to ihe rule is found in the legumes such as 
the clovers and alfalfa, where at maturity the leaves 
unavoidably rattle off and are lost, either before or 
during the process of curing. The fact that growth of 
dry matter takes place up to the time of full maturity is 
well illustrated by the results of experiments conducted 
on the farms of the Pennsylvania State College, the 
New York Experiment Station, and the University of 
Maine, in cutting timothy grass, clover, and maize at 
different stages of growth. These results are sum- 
marized in the accompanying tables: 

Timothy grass (yield of dry hay per acre) 

Results in Pennsyl- 
^-Results in Maine—- vania— two farms 
av. 3 years 1 year av. 2 years 

1878-1880 1889 1881-1882 

Stage of growth lbs. lbs. lbs. 

Nearly in head 3,720 

Full bloom 4,072 4,225 2,955 

Out of bloom or nearly ripe . 4,136 5.086 3,501 

Ripe 3,832 



Influence of the Stage of Growth 209 

Maize for silage {yield of dry matter per acre) 

New York Maine 

1889 180d 

Stage of growth lbs. lbs. 

Tasseled to beginning of ear 1,620 3,064 

Silked to some roasting ears' 3,080 5,211 

Watery kernels to full roasting period . 4,640 6,060 

Ears glazing 7,200 6,681 

Glazed to ripe 7,920 7,040 

Bed clover (yield of dry matter per acre) 

Pennsylvania 
1882 
Stage of growth lbs. 

In full bloom 3,680 

Some heads dead 3,428 

Heads all dead 3,361 

These data are convincing testimony as to the 
growth of dry substance in certain forage crops up to 
and including the period of ripening. Clover is an 
apparent exception, but is probably not really so be- 
cause after the heads begin to die there is an actual 
loss of dry matter from the shedding of the leaves. 

It does not follow when a plant increases in its 
yield of dry matter that its nutritive value has pro- 
portionately increased. The end to be sought is the 
largest possible quantity of available food compounds, 
and it is entirely possible that changes in texture and 
in the composition of the dry substance may partially 
or fully offset the greater yield. With the meadow 
grasses this undoubtedly happens. The dry matter of 
mature grass contains a larger proportion of fiber than 
the immature. • The progressive increase of fiber as 
the plant approaches ripeness is well illustrated by- 
analyses made at the Connecticut Experiment Sta- 

N 



Ash 


Protein 


Crude 
fiber 


Nitrogen- 
free 
extract 


Fats 


4.7 


9.6 


33. 


50.8 


1.9 


4.3 


7.1 


33.3 


53.3 


2. 


4.1 


7.1 


33.8 


53.3 


1.7 


3.6 


6.8 


35.4 


52.2 


2. 



210 The Feeding of Animals 

tion of a sample of timothy grass cut at different 
periods of growth: 

Composition of dry substance {per cent) 

Stage of growth of timothy 
Well headed out .... 

In full blossom 

When out of blossom . 
Nearly ripe 3.6 

These analyses show that the changes are not con- 
fined to an increase of fiber. The relative proportions 
of ash and protein grow less as the plant matures. An 
examination of the nitrogen -free extract would prob- 
ably show an accompanying decrease of the soluble 
carbohydrates. 

The combined effect of these changes is to cause 
the plant to harden in texture and become less pala- 
table. The digestibility is naturally affected. Three 
American digestion experiments with timothy hay cut 
in bloom or before show an average digestibility of the 
organic matter of 61.5 per cent, the average from four 
experiments with timothy cut when past bloom being 
55.4 per cent. Doubtless the increase in dry matter 
when timothy stands beyond the period of full bloom 
no more than compensates for the decrease in digesti- 
bility. Using the average coefficients of digestibility 
and the average yields, as given in this connection, the 
yield of digestible organic matter would be in full 
bloom, 2,306 pounds, and when out of bloom or nearly 
ripe, 2,350 pounds. If one considers the decrease in pala- 
tableness the advantage is with the earlier cut hay. 



Influence of the Stage of Growth 211 

These facts do not pertain to timothy alone. Other 
meadow grasses are similar in their characteristics of 
growth. The clovers, and especially alfalfa, deteriorate 
to a marked degree from the same cause when allowed 
to ripen too fully before cutting. 

It is probable, all factors considered, that if the 
grasses and clovers which are cut for hay could be 
harvested when in full bloom a desirable compromise 
would be effected between quantity and quality. Al- 
falfa should be cut no later than when the first bloom 
makes its appearance. 

Conditions are quite different with maize. This 
plant in maturing gains not only in quantity but in 
quality. In support of this statement data are cited 
from an experiment conducted at the Maine Experi- 
ment Station. 

The following is the composition of the dry matter 
of the corn when cut at several periods of growth : 

In 100 parts water- free substance of maize 

Stage of growth Ash 

Very immature, Aug. 15 9.3 

A few roasting ears, Aug. 28 . . 6.5 

All roasting stage, Sept. 4 6.2 

Some ears glazing, Sept. 12. . . . 5.6 
All ears glazed, Sept. 21 5.9 

Here we see the same decrease in the proportions of 
ash and protein as occurs with timothy, but, unlike 
timothy, the maturing of the maize causes a decrease in 
the percentage of fiber and a material increase in the 
relative amount of the soluble carbohydrates, sugar 
and starch. 



Protein 


Crude 
fiber 


Sugar 


Starch 


Total 
nitrogen 

free 
extract 


Fat 


15. 


26.5 


11.7 




46.6 


2.6 


11.7 


23.3 


20.4 


2.1 


55.6 


2.9 


11.4 


19.7 


20.6 


4.9 


59.7 


3. 


9.6 


19.3 


21.1 


5.3 


62.5 


3. 


9.2 


18.6 


16.5 


15.4 


63.3 


3. 



212 The Feeding of Animals 

These data give us every right to expect that the 
dry matter of the mature corn plant is more digestible 
than that of the immature plant, and experimental 
tests show this to be the case. There follows a sum- 
mary of American digestive experiments bearing on 
this point: 

Digested from 100 parts organic matter 

i — Corn fodder — - < Corn silage « 

Max. Min. Av. Max. Min. Av. 

Cut before glazing, 13 experiments . . 71.4 53.6 65.7 77.8 56.6 67.4 
Cut after glazing, 10 experiments.... 74.2 61.2 70.7 80.2 65.2 73.6 

The advantage is seen to be with the mature corn. 
It is fair to conclude from all these observations that 
harvesting the corn plant when immature is injudicious 
from every point of view. 

SILAGE 

About twenty -five years ago a new process for pre- 
serving crops in a green condition was introduced into 
the United States; viz., ensilage. This consists in 
storing green material in receptacles called silos, in 
masses sufficiently large to insure certain essential con- 
ditions. Within a brief period after maize or other 
green material is packed in a silo, the mass becomes 
perceptibly warm and in the course of two or three 
days it reaches its maximum temperature, which is much 
above the average heat outside. This rise in temper- 
ature is due to chemical changes which involve the 
consumption of more or less oxygen and the produc- 
tion of compounds not previously existing in the fresh 
material. 



Silage Formation 213 

Nature of the changes in the silo. — These changes 
are very complex. They have been regarded as due to 
the activity of a variety of ferments, principally those 
which are believed to cause the formation of alcohol 
and acetic, lactic and other acids. Whether the oxi- 
dations occurring in the silo are wholly induced by 
ferment action or in part at least are the result of 
oxidations brought about in other ways is a point over 
which there has been some recent interesting discussion. 

Babcock and Russell have carried on at the Univer- 
sity of Wisconsin, able and very suggestive inves- 
tigations concerning the causes of silage formation. 
They conclude that the theory that silo changes under 
normal conditions are due wholly to bacteria "does 
not rest on a sound experimental basis.' 7 

Their data lead them to regard respiratory processes, 
both direct by the plant cells and intramolecular, as 
the main causes of the chemical transformations which 
produce carbon dioxid and the evolution of heat within 
the ensiled mass. The direct respiration appropriates the 
oxygen confined in the air spaces of the silo, and the 
intramolecular respiration uses oxygen combined in the 
tissues. Both forms of respiration go on only so long 
as the plant cells remain alive. Concerning bacteria 
the authors say: "The bacteria, instead of function- 
ing as the essential cause of the changes produced 
in good silage, are on the contrary only deleterious. 
It is only where putrefactive changes occur that their 
influence becomes marked." 

Whatever are the inducing causes, the chemist finds, 
when he keeps a careful record of what takes place in 



214 The Feeding of Animals 

the silo, that the silage contains considerably less dry 
substance than the original fresh material. In some 
way loss has occurred through the formation of volatile 
products. An examination of the fresh corn and of the 
silage shows, moreover, that the latter contains much 
less sugar than the former, sometimes none at all. In 
the place of the sugar we find a variety of acids, chiefly 
acetic and lactic. This is a change similar to the for- 
mation of acetic acid in cider and lactic acid in milk, 
in all cases sugars being the basal compounds. Along 
with the development of these acids, carbon dioxid and 
water are formed from the carbon compounds of the 
ensiled material. In other words, combustion takes 
place and more or less of dry matter is actually burned 
up, thus generating heat and causing rise of temperature 
of the fermenting mass. The amount of dry matter 
thus lost is determined partly by the kind of crops 
and the care with which the silo is built and filled. 

Another important chemical change induced by fer- 
mentation is a splitting up of a certain portion of the 
proteids of the fermenting material into amides, com- 
pounds which, as we have learned, have a more limited 
nutritive function than the proteids. Investigation 
conducted at the Pennsylvania State College showed 
that in some cases over half the nitrogen of silage 
existed in the amide form, this being between two and 
three times as much as was found in the original fodder. 
Probably the same change takes place in the field- 
curing of fodder, but no data are available on this point. 

All observers agree so far that with normal silage 
much the larger part of the material lost is sugar. 



Changes and Losses in the Silo 215 

Starch seems to resist the usual silo oxidations. In 
certain experiments a considerable loss of nitrogen is 
reported. It is hard to understand, though, how this 
can occur to any large extent unless the conditions in 
the silo are very bad, so that putrefactive fermentations 
set in. An extensive loss of nitrogen compounds cer- 
tainly would indicate very serious and long -continued 
destructive changes. 

The nature of the changes and losses in producing 
silage have been dwelt upon partly because corn, the 
principal silo crop, is one of our most important forage 
crops, perhaps the most so on a dairy farm, and partly 
in order to illustrate the necessity and value of good 
management in preserving this crop by the silo method. 
Moreover, the loss that is incident to the field -curing 
of maize is practically the same in kind and is fully as 
large as that pertaining to silage, so that the facts pre- 
sented are pertinent to both methods as well as to all 
circumstances where similar oxidations and fermenta- 
tions are likely to ensue. 

Extent of loss in the silo. — The extent of the loss of 
dry substance is important. It measures in a general 
way the difference between the food value of the silage 
and of the fresh material. The silo combustion reduces 
the energy or heat value which the fermented fodder 
will have whenever it is eaten by the animal. The 
heat lost would warm an animal during a cold day were 
the combustion to occur within the animal instead of in 
the silo. It is desirable, therefore, to know the extent 
to which dry substance is actually broken up in the 
preparation of silage. This loss has been measured 



216 



The Feeding of Animals 



by several investigators, and, as was to be expected, 
it has been found to depend greatly upon the condi- 
tions involved, the figures reached varying from about 2 
per cent to nearly 40 per cent of the dry matter of the 
fresh crop. In a majority of cases the loss has been 
over 15 per cent and less than 20 per cent. Professor 
King, of the Wisconsin Experiment Station, who has 
given the production of silage much study, concludes 
upon the basis of his observations that in good prac- 
tice the necessary reduction of dry matter in making 
corn silage need not exceed 4 to 8 per cent, and with 
clover silage from 10 to 18 per cent. The necessary 
loss is explained as being that which occurs in the 
interior of the mass where all outside air is excluded 
and other favorable conditions prevail. Considering 
the contents of the silo as a whole, it will require care- 
ful attention to all details in order to reach Professor 
King's estimate with the best conditions attainable. 

This investigator found that 64.7 tons of silage 
packed in a silo lined with galvanized iron, thus secur- 
ing a perfect exclusion of air, lost an average of 6.38 
per cent of dry matter. This silo was filled in eight 
detached layers, and the proportion of loss in these sev- 
eral divisions, as affected by location, is most suggestive: 

Surface layer. . . 8,934 lbs., lost 32.53 per cent dry matter 



Seventh layer . . 8,722 

Sixth layer 14,661 

Fifth layer 48,801 

Fourth layer ...13,347 

Third layer 7,723 

Second layer . . .12,689 
Bottom layer... 12, 619 



23.38 
10.25 
2.10 
7.01 
2.75 
3.53 
9.47 



Extent of ISilo Losses 217 

The mean loss of dry matter in the lower six layers 
was only 3.66 per cent. These figures show that it is 
profitable to make the walls of the silo air-tight, even 
at large expense. 

The importance of reducing the loss in the silo to 
the lowest possible percentage is almost self-evident. 
As this point is capable of mathematical demonstration, 
it will be interesting and suggestive to calculate what 
might take place in a hundred -ton silo. In many of 
the trials which appear to have been conducted under 
not unusual conditions, a loss as high as 20 per cent of 
the dry matter put in the silo has been observed. In 
a hundred -ton silo filled with corn containing 25 per 
cent of dry matter, or 50,000 pounds, this would amount 
to the destruction of 10,000 pounds of dry food sub- 
stance. As the loss falls chiefly on the sugars or other 
soluble bodies which are wholly digestible, the available 
nutrients in the fresh material are diminished by an 
amount of digestible dry matter, equivalent to what 
would be required by ten milch cows during two 
months. If, therefore, < by good planning and extra 
care this waste could be reduced three -fourths or even 
one -half, the food resources for carrying a herd of 
cows through the winter would be materially increased, 
from five to seven and one -half tons of timothy hay 
being the measure of the saving in a hundred -ton silo. 

Ensiling vs. field-curing. — The question is often 
raised whether ensilage or field - curing is the more 
wasteful method of preserving a forage crop. Con- 
siderable study has been given this matter, and the 
results secured have been taken as a justification of the 



218 The Feeding of Animals 

statement that one method is about as economical as 
the other, which is correct if we consider only the out- 
come of certain comparisons. A general survey of the 
data accumulated shows that on the whole the waste 
has been the larger in field - curing. Observations 
made in six states reveal a loss by the old method 
as low as 18 per cent in only one case, and from 21 
per cent to 34 per cent in all others. Possibly under 
favorable conditions of weather, field -cured corn fodder 
may lose as little dry matter as silage, though this is 
doubtful, but in bad weather the waste from the ex- 
posed fodder is extensive. The greatest advantage in 
silo preservation is that conditions can usually be con- 
trolled with more satisfactory average results than are 
possible in field -curing. Other advantages pertain to 
the silo which are of a business nature and which need 
not be discussed here, further than to affirm- that the 
cost of a unit of food value is in general diminished 
by the use of the silo. 

Crops for ensilage. — The number of crops that may 
be successfully ensiled is not large. Maize is the most 
valuable one for this purpose, and clover is stored in 
this manner with a fair degree of success. So are 
peas, especially when mixed with corn. The true 
grasses and cereal grains outside of corn are not de- 
sirable silo crops, first because the silage from them 
is generally poor in quality, and second because usually 
they may be successfully and more cheaply stored in 
an air -dry condition. Any crop with a hollow stalk, 
giving an enclosed air space, — oats, for instance, — is not 
adapted to silo conditions, and there is no justification 



Construction of the Silo 219 

for ensiling any fodder which is susceptible of prompt 
and thorough drying in the field, because in such cases 
there is an unnecessary waste of food substance by fer- 
mentation and an unnecessary handling of many tons 
of water contained in the green material, with no com- 
pensating advantages. But any crop used for the 
production of silage should be managed in the most 
efficient manner. A few general facts may be discussed 
in this connection. 

Construction of silos. — Silos that are of proper 
construction and shape have air-tight perpendicular 
walls and a height considerably in excess of either of 
the horizontal dimensions. These conditions are essen- 
tial to the completest possible exclusion of air and to 
the closest possible packing of the material, with a 
minimum of exposed upper surface. 

Silos may be either round, square or rectangular, 
provided that in the latter case one horizontal dimen- 
sion is not too greatly in excess of the other. The 
shape of a silo which is most economical and efficient 
is not the same for all conditions, although the round 
and square forms hold most in proportion to the wall 
area. Many farmers desire to have the silo in the barn, 
and generally there the square or rectangular form is 
more economical of space than a round one. When 
built outside the barn, the round form, according to 
the opinion of many, may be used to advantage both 
as to expense and results. If a square or rectangular 
silo is built the corners should be cut off inside in 
order to prevent an access of air and the decay which 
occurs at those points when this is not done. Several 



220 The Feeding of Animals 

kinds of materials have been used in building silos, 
wood, brick, and stone, the former material proving to 
be the most satisfactory. If the walls are of masonry 
the inner surface must be cemented not only air-tight 
but so smoothly as to allow easy and uniform settling 
of the silage without leaving air spaces. If wood is 
used, which is certainly to be preferred, the inside con- 
struction must meet the same requirements. Lining a 
wooden silo with iron has been suggested as practical 
and economical. Economj- demands that as a pre- 
ventive against decay the inner woodwork should at 
least be treated with some preservative, which may also 
serve the purpose of obviating excessive swelling and 
shrinking of the lining boards. 

Filling the silo. — The condition of the crop and the 
manner of filling a silo determine to a great extent the 
character of the silage. Obviously it should be so 
done as to reduce the loss of food compounds to the 
lowest possible point. Three points are prominently 
discussed in this connection: (1) the condition of the 
crops; (2) the preparation of the material, and (3) the 
rate of filling. 

Experience has thoroughly demonstrated that the 
maturity of a crop influences its value for silage. This 
is known to be especially true of the corn crop. An 
immature corn fodder, which always carries a high 
percentage of water with less of the matured products, 
such as starch, is always certain to change to very acid 
silage. On the contrary, mature corn, when properly 
handled, is converted into a product with the minimum 
acidity and with an appearance and aroma much 



Filling the Silo 221 

superior to that from the immature plant. Neither are 
satisfactory results secured from material that is over- 
dry. It may be stated in general terms that the best 
results are obtained when the proportion of dry matter 
falls between 25 per cent and 30 per cent. If corn is 
harvested for the silo after the kernels have begun to 
glaze, while the leaves are still green and before they 
show dryness, other conditions being favorable, it will 
meet every requirement for good silage. 

Whether the material with which a silo is filled shall 
be put in whole or after cutting or shredding depends 
to quite an extent upon its degree of coarseness. It is 
probable that clover, and even the smaller varieties of 
maize, are often successfully preserved without cutting, 
but no one professes that this can be done with the 
coarser varieties of maize. It is generally admitted 
that, with maize, cutting or shredding it increases the 
probability of satisfactory preservation, because the 
finer mechanical condition allows more uniform pack- 
ing and prompter and more uniform settling. The 
highest grade of silage with the minimum loss is 
undoubtedly more surely made from cut or shredded 
material. 

In the early days of silos it was taught that to 
insure the least possible waste by fermentation, the silo 
should be filled with the maximum rapidity and then 
promptly weighted. Following this view was the con- 
clusion on the part of some that very slow filling with 
no packing other than that given by the weight of the 
mass, was the proper way to make silage of the highest 
quality. This method was advocated for producing 



222 The Feeding of Animals 

sweet (?) silage. It allowed violent fermentation at 
first with resulting high temperatures, by which means 
bacteria were supposed to be killed and subsequent 
fermentations prevented, a conclusion so far not sus- 
tained by scientific observations. At the present time 
moderately slow and continuous filling, rather than 
very rapid, is advocated by leading authorities. Two 
advantages are claimed for this method, one being that 
more material can be stored in the silo and the other 
is that silage of a higher quality is produced with a 
smaller loss of dry matter. The first point must be 
conceded and the second claim may be true, although 
in part it lacksiDroof. It is hard to understand why slow 
filling, especially if intermittent, should not increase 
rather than decrease the losses of food compounds. 
Certainly the less compact the mass the more intense 
the oxidation and the higher the temperature, the latter 
condition indicating with certainty the extent of the 
combustion. This point is illustrated by results reached 
at the Pennsylvania State College when the chemical 
changes in two large tubs of sorghum silage were 
studied, one of which was compactly filled and weighted 
at once and the other loosely filled and weighted after 
five days. The temperature rose seventeen degrees 
higher in the latter than in the former, with a loss of 
two and one -half times as much organic matter from 
the loosely filled tub. It follows from the theory of 
Babcock and Russell, previously noted, that the less 
the oxygen available in the air spaces and the quicker 
the plant tissue dies the less will be the combustion or 
loss of organic matter. These authors suggest as a 



The Straws 223 

practical application of their theory that the air be 
excluded from the silo as rapidly as possible and only 
mature corn be ensiled, because such tissue will die 
sooner than immature, having less vitality. Their data 
seem to prove conclusively, also, that the evolution of 
much heat when a fodder is first ensiled is not essential 
to the formation of first-class silage. The repeated 
exposure of a loose upper stratum, which occurs with 
slow, intermittent filling, must cause extensive loss 
from portions of the silo. It must be held, in view of 
the experimental data now at hand, that the more 
promptly the air is excluded and expelled by the re- 
duction of the contents of the silo to a condition of 
maximum compactness, the less will be the fermenta- 
tion losses. The term "sweet silage" means but little 
as indicating completeness of preservation, for it may 
even be the result of extensive fermentations, a condi- 
tion expensively secured. Its significance is entirely 
different when the sweetness is due to proper maturity 
of the fodder plant. 

THE STRAWS 

When the grain plants which produce seeds val- 
uable for cattle and human foods are threshed, 
or in some way manipulated to remove the seeds, 
the other parts of the plant constitute what we call 
straw in the case of the cereal grains and le- 
gumes, and stover in the case of maize. These fod- 
ders differ from the same plants, when cut in a less 
mature condition for haj r or fodder, in being more tena- 



224 The Feeding of Animals 

cious and less palatable, with a smaller proportion of 
the more soluble, and therefore more valuable, com- 
pounds. The most useful of these materials for feed- 
ing purposes are corn stover, oat straw, and the legume 
straws. These are better relished by farm animals than 
wheat and barley straws, which are utilized mostly 
for litter. 

ROOTS AND TUBERS 

Certain species of plants, more especially beets, 
mangel -wurzels, turnips, rutabagas, carrots and pota- 
toes, are agriculturally valuable because of the store 
of nutrients which they deposit in subterranean branches 
or in roots. The origiual purpose of this deposit is, 
in the case of potatoes and artichokes, to nourish the 
young plants of the next generation, or, in the case 
of biennials like beets, to supply the materials for the 
seed -stalk and seeds of the second year. Potatoes are 
not grown primarily as food for cattle, but roots have 
for many years been a standard crop for feeding pur- 
poses, especially in the production of mutton and beef. 
This class of crops has the advantage of furnishing 
very palatable, succulent food, which may be kept in 
perfect condition during the entire winter season, an 
advantage which is not wholly measured by the actual 
quantity of nutrients supplied by these materials. 

The disadvantages of these crops are that they are 
somewhat expensive to grow and necessitate the han- 
dling of large weights of water. A ton of turnips or 
mangels may furnish even less than 200 pounds of dry 
substance, to secure which 1,800 pounds of water must 



Boots, Grains and Seeds 225 

be lifted several times. The percentage of dry matter 
in roots and tubers varies in American products, on 
the average, from 9.1 per cent in mangel -wurzels and 
turnips to 28.9 per cent in sweet potatoes. Potatoes 
are more nutritive pound for pound than roots. The 
dry matter of this class of cattle foods is principally 
carbohydrate in its character, though the proportion 
of protein is as large and in some cases larger than in 
certain grain foods. 

Two conditions are essential to the winter storage 
of roots without deterioration; viz., a low temperature, 
as near freezing as possible, and abundant ventilation. 
Large masses of roots unventilated are apt to "heat," 
and sometimes decay, with a resulting large loss in 
nutritive value. 

GRAINS AND SEEDS 

The conditions which provide for the maintenance 
of plant life also subserve the interests of the animal 
kingdom. We have seen that this is true of the store 
of starch and other compounds in tubers and roots, 
and it is a fact of much larger significance in the 
production of seeds, especially those of our cereal 
grains, including barley, maize, oats, rice, rye and 
wheat. Other seeds, such as buckwheat, cottonseed, 
flaxseed, beans and peas, also contribute an important 
addition to our animal feeding stuffs. In all these 
species there is deposited in the seed-coats and either 
around the chit or embryo or in the seed-leaves of the 
embryo, a store of protein, starch and oil, the purpose 
of which is to supply materials for growth during 



226 The Feeding of Animals 

germination. This deposit of plant compounds repre- 
sents the highest type of vegetable food, whether we 
consider concentration, palatableness or nutritive effi- 
ciency. Besides, it is in such form that with ordinary 
precautions it is capable of indefinite preservation, 
without loss. 

It often occurs that when newly -harvested grain 
is stored in bulk it heats and grows "musty." This 
condition is due to fermentations that are made pos- 
sible by the high water content of the fresh grain and 
which involve a loss of dry substance. It is very de- 
sirable that grain shall be thoroughly dried before 
threshing, and it is generally necessary to secure 
additional drying after threshing before storing it in 
large bins. 

The agricultural value of the cereal grains is much 
enhanced by their adaptability to a great range of 
soil and climatic conditions. They are the American 
farmer's great reliance for the production of the high- 
est class of cattle foods. Maize, especially, is grown 
from Maine to Florida and from the Atlantic to the 
Pacific. These crops are useful, not only for their 
seeds but as fodder plants. For soiling purposes, as 
well as a source of dried forage, they are indispen- 
sable. 



CHAPTER XVI 

CATTLE FOODS— COMMERCIAL FEEDING STUFFS 

The cereal grams and other seeds are the source of 
a great variety of by-product feeding stuffs which have 
a large and widespread use, especially in the dairy 
sections of the United States. In the preparation of 
a great variety of human foods and of other materials 
important in industrial life, certain by-products are 
obtained which represent particular parts or compounds 
of the grain or seed. Whenever the methods of manu- 
facture are such as not to injure the palatableness or 
healthfulness of these waste products, they may be 
utilized as cattle foods. As a matter of fact, a large 
proportion of our commercial feeding stuffs is of this 
general kind and because these materials differ greatly 
in composition and nutritive value, the purchaser should 
clearly understand their source and character. Changes 
in methods and new manufacturing enterprises are 
constantly modifying the composition of old products 
aud introducing new ones, consequently the facts as 
they exist at one time may not be applicable for a 
long period. There is need therefore of constantly 
keeping informed in regard to the various cattle foods 
found in the markets, if they are to be economically 
purchased and wisely used. 

(227) 



228 The Feeding of Animals 

CLASSES OF COMMERCIAL BY-PRODUCT FEEDING STUFFS 

For the purposes of description, the various by- 
product feeding stuffs may be classified according to 
their origin. Their sources are mainly as follows: 

1. The milling of wheat and other grains. 

2. The manufacture of oatmeal and a variety of 

breakfast foods. 

3. The manufacture of beer and other alcoholic 

drinks. 

4. The manufacture of starch and sugars, chiefly 

from corn . 

5. The extraction of oils, chiefly linseed oil and 

cottonseed oil. 

Wheat offals. — No commercial feeding stuffs are 
regarded with greater favor, or are more widely and 
largely purchased by American feeders than the by- 
products from milling wheat. Wheat -bran and mid- 
dlings are cattle foods of standard excellence, whether 
we consider composition, palatableness or their relation 
to the quality of dairy products. These feeding stuffs 
consist of particular parts of the wheat kernel, a knowl- 
edge of the structure of which aids greatly in under- 
standing what they are and why they possess certain 
chemical and physical properties. 

To ordinarj^ observation the wheat grain appears to 
be merely a seed, but it is really a seed contained in a 
tightly - fitting seed -pod. This pod, which is woody and 
tough, constitutes the outer coating of the kernel. On 
the seed itself are two more hard and resisting coat- 
ings, one of which is double, that* serve to protect the 



Structure of the Wheat Kernel 



229 



softer parts. We find, then, that in every wheat ker- 
nel there are three coats entirely unlike the rest of the 
grain, because they consist of hard, thick- walled cells 
containing but little starch, if any, with a much larger 
proportion of cellulose or fiber than is found in the 
inner portion of the kernel. Figs. 4 and 5. 

Just inside the innermost of the three outer coats 
is a layer of material very rich in protein compounds, 




Fig. 4. Section of entire wheat kernel (enlarged 16 diameters). 
1, Seed pod and seed coatings. 4, Gluten layer. 5, Mass of starch cells. 

which may properly be called the gluten layer. The 
great bulk of the wheat kernel is made up of cells 
closely filled with starch grains. This is the soft white 
portion of the seed and is that which furnishes the 
flour. All of these parts serve to protect, and, in ger- 
mination, to nourish the essential portion of the seed, 
the germ or embryo which lies "at the lower end of the 



230 



The Feeding of Animals 



rounded back of the kernel." Bessey, in an admirable 
description of the wheat kernel, tells us that the per- 
centage proportions of its various parts are as follows: 



Per cent 

Coatings 5 

Gluten layer 3-4 



Per cent 

Starch cells 84-86 

Germ 6 



We are now prepared to understand the significance 
of the statement that in milling wheat the flour of 




Fig. 5. Partial section of wheat kernel (enlarged 155 diameters). 
1. Seed pod. 3. Inner seed coat. 



2. Outer seed coat. 



4. Gluten cells. 



5. Starch cells. 



various grades comes from the starch cells, the other 
portions passing into the bran, shorts and middlings, 
which collectively are termed the offal. If only the 
coatings, gluten layer and germ went to make up the 
offal it would include only about 14 or 15 per cent 
of the kernel, the flours taking the remainder, but, as 
a matter of fact, no milling methods so far used com- 
pletely separate the starch cells from the enclosing tissue, 
so that the offal is perhaps never less than 25 per cent 



Offals from Milling Wheat 231 

of the whole grain. In milling tests conducted by the 
Minnesota Experiment Station, the offal from several 
lots of wheat, good and bad, varied from 25 per cent 
to 40 per cent. If four bushels of wheat are consumed 
per capita by the population of the United States, 
which is below the estimate, and if only one-quarter of 
this is converted into offals, the amount of bran and 
middlings annually consumed by our domestic animals 
is 2,250,000 tons, barring the quantity which may be 
exported. 

It is a fact worthy of special comment that because 
of a somewhat irrational standard of excellence for 
bread, certain parts of the wheat kernel best adapted 
to the nourishment of young and growing animals are 
separated with great care to be used by the brute life 
of the farm rather than by the farmer and his family. 
A comparison of the composition of the whole wheat 
kernel, white flour and the various parts of the offal 
emphasizes this point. The figures given are taken from 
the results of an investigation by Snyder, of Minnesota, 
in which he compared the composition of different 
grades of wheat with that of the flour and products 
obtained from them: 

Composition of tcheat and its milling products (per cent) 





Water 


Ash 


— Protein — « 
Total Gluten 


Fiber 


Nitrogen- 
free 
extract 


Starch 

and dex 

trine 


Pat 


Wheat kernel. . 


10.2 


1.8 


13.7 


13.5 


3.2 


69. 


64.9 


2.0 


Wheat flour — 


, 10.6 


.4 


11.2 


11. 




77.3 


70.4 


.5 


Wheat germ . . . 


10.4 


2.7 


15.7 


15.3 




67.7 




3.5 


Wheat shorts . . 


10.1 


3.1 


13.1 


12.9 


5.4 


65.3 




2.9 


Wheat bran. . . 


. 10.4 


5.9 


15.4 


14.8 


10.2 


52.9 




5. 



232 The Feeding of Animals 

The greater richness of the coatings of the kernel 
in mineral matter, protein, fiber, and oil is made plain 
by this comparison. There is four times as large a 
percentage of mineral matter and of oil in the whole 
wheat as in the flour, nearly one -third more protein 
and considerably less starch. On the other hand, the 
bran is not less than ten times richer in mineral com- 
pounds and oil than the flour, one -third richer in pro- 
tein, with correspondingly less starch. "Graham" flour, 
which contains more or less of those parts which pass 
into the offal in milling white flour, does not differ so 
much from the whole kernel. Middlings differ from 
bran in containing less of the hard, tough coatings and 
more of the finer parts of the kernels, and this feed- 
ing stuff varies from the coarser kinds to the fancy 
middlings, according to the proportion of starchy ma- 
terial present. Red Dog flour is counted among the 
offals from milling wheat, and it represents the dividing 
line between the middlings and the high-grade flour. 

There is a belief more or less prevalent that bran 
from the old milling processes which contained more 
of the starchy part of the kernel than is now the 
case, was more valuable than roller process bran is. 
It is probable that a greater proportion of starch in- 
creases the digestibility of bran, and in this sense the 
old process bran was superior to the roller process 
product; but, on the other hand, the latter is more 
nitrogenous than the former and is therefore more effi- 
cient as a protein supplement to home -raised foods. 

Residues from breakfast foods. — In the manufacture 
of breakfast foods, the use of which has become so 



By -products from Oats 



233 



prevalent, certain by-products are obtained which are 
now found in the market as cattle foods. The prepa- 
ration of oatmeal and similar materials involves the 
selection of the finest oat -grains, i. e., those having 
the largest kernels, from which the hulls are removed. 
These hulls and the smaller oat -grains, and perhaps 
bran, constitute by-products which, after being finely 
ground, are sold as oat -feed and in various mixtures. 




Fig. 6. Section of entire oat grain (enlarged 16 diameters). 
0. Hull. 1. Seed coat. 4. Gluten layer. 5. Mass of starch cells. 

As the sale of oat hulls as such, or in a fraudulent 
way when mixed with other substances, is likely to 
occasion a financial loss to feeders, it is desirable to 
clearly understand the situation. We shall accomplish 
this by a study of the relation of the oat hulls to the 
kernel in quantity and composition. Figs. 6 and 7. 

It is common knowledge that the oat -grain con- 
sists of a hull and kernel, which are easily separated. 
The former is fibrous and tough, and the latter soft 
with very little fiber. The hull forms a considerable 
portion of the grain. In 1894, the Ohio Experiment 



234 The Feeding of Animals 

Station made a study of numerous varieties of oats. 
It was found that with sixty -nine varieties the hulls 
constituted from 24.6 per cent to 35.2 per cent of the 
whole grain, the average being 30 per cent. It did 
not appear, contrary to the general opinion, that the 
proportion of hull was larger with light oats than with 
heavy, although observations elsewhere have sustained 
the popular view. At the Mustiala Agricultural Col- 
lege twenty -eight samples of Finnish oats and twenty 
samples from five other counties gave from 28 to 32 per 
cent of hulls. Wiley states that the average propor- 
tion of hull to kernel is as three to seven, which varies 
with the locality in which the oats are grown. The 
figures in the next table show the composition of 
the dry matter of whole oats, oat hulls and the hulled 
kernel : 

Nitrogen- 
free 
Ash Protein Fiber extract Fat 

% % % % % 

Whole oats, 30 samples 3.4 13.2 10.8 67. 5.6 

Hulls, New Jersey 7.2 3.5 32. 56.3 1. 

Hulls, Vermont 6.9 4.4 29.5 57.2 2. 

Hulls, Wisconsin 7.8 2.3 50.1 39. .8 

Hulled kernels, 179 analyses . 2.3 15.4 1.5 72.1 8.7 

The inferiority of the hulls as compared with the 
whole grain or with the hulled kernels is very appa- 
rent, because of their smaller proportion of protein 
and oil and their much larger percentage of fiber: If 
hulls are purchased at all the price should be on a par 
with that at which the coarsest and cheapest grades 
of fodders are sold, and the surprisingly prevalent dis- 
honest adulteration of ground whole grains with oat 



Residues from Barley and Com 



235 




^f^&0ii '~7H 



hulls should in some way be prevented by official in- 
spection. Farmers will do well to carefully inquire 
into the character of the so-called oat feeds and mixed 
feeds offered to them. These articles are often oat 
hulls, poor oats and other refuse mixed with corn or 
with by - products of an- 



other class and are dis- 
tinctly inferior to the 
whole grains. Such low 
grade mixtures are not 
wisely purchased at prices 
nearly equal to those rul- 
ing for whole cereal grains 
of any kind. 

Other grains besides 
oats are used as the source 
o f specially prepared 
human food. Barley feed, 
a by - product from the 
manufacture of pearled 
barley, like oat feed con- 
sists of the hulls and por- 
tions of the grain and 
contains more fiber and 
less starch than the origi- 
nal grain, its value being proportionately less. Hominy 
is made from corn and consists of the hard portions of 
the kernel, leaving as a residue the hull, germ, and part 
of the starch cells, which collectively are sold as hominy 
feed or chop. This differs from the whole kernel but 
little in composition and is practically as digestible. 




Fig. 7. Partial section of oat grain 
(enlarged 170 diameters). 

0. Hull. 4. Gluten cells. 

1. Seed coat. 5. Starch cells. 



236 The Feeding of Animals 

Brewers 1 by -products. — Sugar in some form is at 
present essential to the production of alcoholic bev- 
erages, a cheap supply of which is obtained by con- 
verting the starch of certain cereal grains into maltose, 
which afterward passes into fermentable sugars. This 
result is accomplished by placing barley and other 
grains under such conditions of moisture and tempera- 
ture that they germinate. We have already seen that 
during germination the starch of a seed is converted 
into maltose through the action of a diastatic ferment, 
and the maltster arrests this germination at a point 
which gives the maximum quantity of sugar. The 
malted grains^ are subsequently dried and the sprouts 
after removal appear in our markets in an air -dry con- 
dition, constituting one of our valuable nitrogenous 
feeding stuffs. The malted grains are then crushed, 
the sugar is extracted from them, and the residue is 
known in commerce as brewer's grains, a by-product 
feeding stuff fairly rich in protein. The high propor- 
tion of protein is due to the fact that the starch has 
been partially used up, leaving the other constituents 
behind in a more concentrated form. These grains are 
mostly dried and may then be shipped to distant mar- 
kets in a perfectly sound and healthful condition. 

Residues from starch and glucose manufacture. — 
Within a comparatively recent time the gluten meals 
and feeds have assumed an important place among 
our commercial feeding stuffs. These materials and 
others bearing related names vary within wide limits 
in texture and composition, and concerning their quali- 
ties and value there has existed among the farmers 



Structures of the Maize Kernel 



237 



much confusion of thought. Even the best informed 
have not always been promptly cognizant of new 
products of this class or of changes in the compo- 
sition of older ones, so rapidly have new methods of 
manufacture developed. 

The gluten meals, gluten feeds, corn bran, and the 
like are residues obtained in the manufacture of starch 
and glucose from the maize kernel. This kernel, like 










Fig. 8. Section of entire maize kernel (enlarged 10 diameters). 

1. Outer layer of husk or skin. 2. Inner layer of skin. 4. Gluten layer. 

5. Mass of starch cells. 

that of wheat, is not homogeneous in structure and 
composition, a condition which makes it possible, 
through mechanical or chemical operations, to secure a 
variety of by-products greatly unlike in texture and in 
their proportions of nutrients. 

All this is made plain through a consideration of 
the structure of the maize kernel. This seed is in some 
respects similar to that of wheat. We have first an 
outside husk or skin made up of two distinct layers, 
one less than we find in wheat. This skin is rich in 



238 The Feeding of Animals 

fiber, scarcely any being found in the other portions 
of the kernel. Next on the inside is a layer of cells 
rich in gluten. The body of the kernel surrounding 
the germ or embryo consists of closely compacted 
starch cells, though some of this interior tissue on the 
sides of the kernel next to the walls is flinty. We 
may property speak of the maize kernel, then, as 
consisting of four parts, — the husk, the gluten layer, 
the germ, and the starchy and hard part. Figs. 8 
and 9. At the New Jersey Experiment Station 100 
grains of the maize kernels were separated as nearly 
as possible into the skin, germ, and main or starchy 
and hard portions. These parts were analyzed, and 
below are given the results: 

Composition of dry substance of maize kernel (per cent) 

Nitrogen- 
free Proportion 
Ash Protein Fiber extract Fat of parts 

Original kernel 1.7 12.6 2. 79.4 4.3 100. 

Skin 1.3 6.6 16.4 74.1 1.6 5.5 

Germ 11.1 21.7 2.9 34.7 29.6 10.2 

Starchy and hard part . .7 12.2 .6 85. 1.5 84.3 

These figures are essentially similar to those obtained 
by other investigators, including Salisbury, Atwater, 
and Balland. 

The separation of starch cells from other parts of 
the kernel is now accomplished mechanically. Either 
before or after soaking in warm water, the maize ker- 
nels are crushed into a coarse powder. The various 
parts separate in water by gravity, the hulls floating 
on the surface and the germs sinking to the bottom. 
The starch and harder portions of the kernel remain 



By-products from Maize Kernel 



239 



in suspension in the water, which is conducted slowly 
through long troughs, where the starch settles to the 
bottom and the more glutinous portions float off and 
are recovered. 

It is now easy to see how these various by- 
products may differ widely. When made up largely of 
the hulls or bran they are characterized by a relatively 




Fig. 9. Partial section of maize kernel (enlarged 170 diameters). 
1. Outer layer of skin. 2. Inner layer of skin. 4. Gluten cell. 5. Starch cells. 

high proportion of fiber with comparatively low per- 
centages of protein and fat. The presence of the 
germs increases the relative amount of protein some- 
what and of the fat very greatly. The fine glutinous 
part, that is finally separated from the starch, when 
unmixed with other materials is distinguished by its 
high content of protein. 

As found in the market, the principal brands 
are "sugar corn" or "starch" feed, made up mostly of 
hulls and germs; gluten meal, that comes from the flinty 
portion of the kernel, and gluten feed, which is now a 



240 The Feeding of Animals 

mixture of hulls and the gluten part. When unmixed 
with other parts of the kernel, the hulls are also known 
as corn bran and the germ portion from which the 
oil has been pressed is called, when ground, germ oil 
meal. The corn bran contains the least protein and the 
gluten meal the most, while the gluten feed and germ 
oil meal occupy a position between these. It should 
be remarked that the commercial names for gluten prod- 
ucts are not always a safe guide in their purchase. 

Residues from the manufacture of beet sugar. — An 
industry apparently now on the increase in the United 
States, the manufacture of beet sugar, is offering to 
farmers two waste products, sugar beet pulp and sugar 
beet molasses. The former is the extracted beet tissue 
from which all the sugars and more or less of other 
soluble compounds have been removed. This pulp as 
it leaves the factory has been found to contain an 
average of scarcely 10 per cent of solids. One ton of 
pulp supplies, then, not over two hundred pounds of 
total dry substance, or perhaps one hundred and sixty 
pounds of digestible dry substance. This means that 
it would require six tons of pulp to supply as much of 
digestible nutrients as one ton of good hay. The solids 
of the pulp must be regarded as inferior to those of the 
beets before extraction, because consisting more largely 
of fiber and gums whose productive value is below that 
of sugar. Experiments at Cornell University indicated 
that the pulp is worth about one- half as much as corn 
silage, which would be approximately the proportion of 
digestible matter in the two materials. 

Sugar beet pulp is, however, a useful, succulent 



Residues from the Oil Seeds 241 

food, and may be fed to advantage in quantities from 
seventy-five to one hundred pounds daily to full-grQwn 
animals, provided it can be purchased at a price pro- 
portional to its value. 

The pulp is not adapted to transportation for long 
distances because of the heavy expense of freight and 
handling, but is most available for consumption near 
the factories. It may be preserved in pits or silos. 

The molasses is generally four-fifths or more dry 
substance and contains from 40 to 50 per cent of sugar, 
which is all digestible and which gives to this product 
its only value for feeding purposes. 

This material has been fed successfully to bovines 
and swiue. When given as an addition to coarse foods 
and home -raised grains it obviously should be combined 
with some nitrogenous feeding stuff like gluten meal 
or the oil meals. 

The oil meals in general. — Materials of this class 
may properly be regarded as among the standard feed- 
ing stuffs. Because of their uniformity in quality and 
composition, their general usefulness in compounding 
rations and their value in maintaining soil fertility, 
their use has had the sanction of scientific men and of 
successful practice. The oil meals are so called be- 
cause they are the residues left after the extraction 
of the oil from certain seeds and nuts, among which 
are cottonseed, flaxseed, hemp and poppy seed, rape 
seed, sesame seed, sunflower seed, cocoanuts, palm 
nuts, peanuts, and walnuts. Of the residues from 
these sources, those from cottonseed and flaxseed 
are most common in the United States; in fact, no 



242 The Feeding of Animals 

other oil meals have become important in our cattle 
feeding. A description therefore of the production of 
cottonseed meal and linseed meal will not only cover 
the points of practical interest to American feeders, 
but will serve to illustrate the main facts that pertain 
to the manipulation of these oil seeds. 

It uiay be stated in a general way that two 
methods are used for removing vegetable oils from 
seeds, expressing bj r pressure and extraction with a 
solvent, both of which are now in use. In using the 
first method, it was formerly the custom to express the 
oil from the cold crushed seed, but now the seed is more 
generally submitted to heat, either by boiling or steaming, 
afterwards applying the pressure to the warm material. 
More oil is obtained by the latter process. The second 
or extraction method involves the use of a solvent, gen- 
erally a light naphtha, which leaves less oil behind 
than either cold or warm pressure. Before extraction 
the crushed seed is heated just as when pressure is used. 

Cottonseed meal. — The cottonseed as gathered from 
the plant consists on the exterior of a mass of long 
white fibers that are attached to the outer coat or hull, 
inside of all of which is the kernel or meat. The seed 
is first delinted by running it through a gin, which 
removes the lint or cotton of commerce. After this 
operation there is still attached to the seed a soft down, 
which is subsequently removed and which constitutes 
what is known as "linters," a short lint that is used 
in making cotton batting. The remaining portion is 
that from which cottonseed oil and certain by-product 
feeding stuffs are produced. 



Cottonseed By-products 243 

The first process in the manufacture of the oil is 
to remove the hull from the inside meat. This is done 
by a sheller, which breaks the seed -coat and forces it 
from the kernel. These seed -coats, which constitute 
from 45 to 50 per cent of the delinted seeds, are known 
in commerce as cottonseed hulls, and are used to some 
extent as a feeding stuff. They are characterized by a 
very low proportion of protein and a very high con- 
tent of fiber. Twenty -two analyses show a range of 
protein from 1.6 per cent to 4.4 per cent, and of fiber 
from 35.7 to 66.9 per cent. Such material as this be- 
longs with the very lowest grade of coarse fodder, as 
both composition and experience demonstrate. The 
hulless kernels make up from 50 to 55 per cent of 
the delinted seed, and from those the oil is obtained. 
These meats are first cooked twenty or thirty minutes 
in large, steam -jacketed kettles in order to drive off the 
water and render the oil more fluid, and then after 
being formed into cakes in wire cloths, they are sub- 
mitted to a pressure of 3,000 to 4,000 pounds to the 
square inch. This removes at least four -fifths of the 
oil and leaves the cakes very solid, which after dry- 
ing are cracked and then ground into a fine meal, 
known in commerce as cottonseed meal. Formerly a 
ton of ginned seed yielded the following quantities of 
the different parts: 

Linters 20 pounds 

Hulls 891 ' ' 

Cake or meal 800 " 

Crude oil , 289 " 

Since the above estimate was prepared the manufac- 



244 • The Feeding of Animals 

turing process has been so improved that from forty 
to forty -five gallons of oil are now obtained from a 
ton of seed, giving a correspondingly smaller amount 
of cake. Chemists are well aware that cottonseed 
meal at the present time is less rich in oil than was 
the case a few years ago. 

When we learn that no less than 1,500,000 tons of 
cottonseed are worked annually at oil mills, which in- 
volves the production of about 600,000 tons of meal, 
we realize the importance of this by-product feeding 
stuff, and the future possibilities are seen in the fact 
that only about one -third of the seed now grown finds 
its way to the oil mills. The composition of the cotton 
oil by-products may properly be stated in this con- 
nection : 













Nitrogen- 














free 






Water 


Ash 


Protein 


Fiber 


extract 


Fat 




% 


% 


% 


% 


% 


% 




, 9.9 


4.7 


19.4 


22.6 


24. 


19.4 


Cottonseed hulls. . 


.11.4 


2.7 


4.2 


45.3 


34.2 


2.2 


Cottonseed kernels 


. 6.9 


6.9 


30.3 


4.8 


21.4 


29.6 


Cottonseed cake. . 


. 8.6 


7. 


44.1 


4.9 


21.2 


14.2 



These figures represent the composition of the several 
materials when the separations are fairly complete. 
Cottonseed products are sometimes sold, however, in 
a more or less mixed condition. There has been found 
in the market undecorticated cottonseed meal, or the 
meal with all the hulls ground in without removal 
from the seed. Practically all the meal found in the 
markets now is the decorticated, or that free from 
hull. This should be light yellow in color and have a 
slightly nutty flavor. It should show few or no black 



Linseed Meal 245 

specks, because the presence of these indicate either 
accidental or intentional adulteration with hulls. Cot- 
tonseed feed, which appears to have found only a 
limited use, is a finely -ground mixture of cottonseed 
hulls and cottonseed meal, and its value is usually 
much less than that of the pure meal. 

Linseed meal (oil meal) . — The original source of 
this feeding stuff is the flax plant. This plant serves 
a very useful purpose in producing a valuable fiber, 
an oil which now seems indispensable as a constituent 
of paint and a high class stock food. Flaxseed, of 
which the annual production in this country averages 
about twelve million tons, contains a very high per- 
centage of oil, ranging in the analyses so far made 
from 22 to 40 per cent. The average is variously 
stated by different compilers at from 33 to 37 per cent, 
and the mean of these two numbers is probably fairly 
correct. On this basis a bushel of flaxseed, weighing 
fifty -six pounds, contains nineteen and one -half pounds 
of oil and thirty -six and one -half pounds of other 
substances. 

Linseed oil is obtained from the seed by both the 
pressure and extraction methods. The oldest method 
was to subject the cold crushed seeds to a heavy pres- 
sure, which expressed from 70 to 80 per cent of the 
oil, leaving a cake containing from 10 to 15 per cent. 
Later the warm pressure process was introduced, which 
consists of moistening the crushed seed, heating it to 
from 160° to 180° Fahr., and submitting it to a pressure 
of 2,000 to 3,000 pounds per square inch. This im- 
provement increased the output of oil from a given 



246 The Feeding of Animals 

quantity of seed, the amount expressed being about 
90 per cent of the whole, leaving a cake containing 
from 6 to 7 per cent. The latest and most effective 
process is the extraction of the oil by a light naphtha. 
The seed is crushed and heated as in the warm pres- 
sure method, and the oil is then extracted by repeated 
teachings with naphtha until the residue when dry 
contains only about 3 per cent of oil. The naphtha is 
thoroughly driven from this residue with steam so that 
the resulting meal is entirely free from odor and is as 
palatable as the residue from the pressure process. 

The terms "old process" and "new process" are 
now applied to linseed meal, the former referring to 
that made by the cold and warm pressure processes 
and the latter to the residue from naphtha extraction. 
The composition differences between the two is seen 
in the following average of several analyses of each 
kind which were made by Woll : 





Water 

% 


Ash 

% 


Protein 

% 


Nitrogen- 
free 
Fiber extract 

% % 


Fat 

% 


Old process linseed meal. 


. 9.4 


5.4 


35.6 


7.1 35. 


7.5 


New process linseed meal. 


. 9.2 


5.4 


36 6 


8.6 37. 


3.2 



These averages show 1 per cent more protein and 
3 per cent less fat in the new process meal. 

The old process samples analyzed by Woll were 
doubtless from the warm pressure methods and do not 
fairly represent the linseed which was found in the 
markets when it first came into general use. Four 
hundred and twenty -eight analyses of old process cake 
compiled by Dietrich and Konig, which were made pre- 
vious to 1888, show an average of only 28.6 per cent 



Linseed Meal 247 

of protein and 10.6 per cent of fat. An average by 
the same authors of 179 analyses of the meal shows 
30 per cent of protein and 9.9 per cent of oil, those 
samples taken previous to 1880 being poorer in pro- 
tein and richer in fat than those analyzed after that 
date. The average of twelve samples of linseed cake 
made prior to 1883 and compiled by Jenkins, gives 
29.7 per cent of protein and 11.2 per cent of fat. 
There is no question but that the meal now found in 
the markets is considerably richer in protein and 
poorer in fat than that with which American farmers 
were first acquainted. 

The relative values of the old and new process 
meals are much discussed. Many farmers are preju- 
diced in favor of the former, possibly because any- 
thing which has been treated chemically is regarded 
with suspicion when considered as a food. No good 
evidence exists, however, that new process meal is less 
palatable or less healthful than the old process prod- 
uct, nor has practice demonstrated that in a general 
way it is less nutritious. 

A very useful inquiry by Woll into the charac- 
teristics of the two kinds of meal showed certain 
differences which are interesting in this connection. 
Two points were studied : the digestibility and the 
property of swelling to a mucilaginous condition when 
stirred up with water. Experiments with animals both 
in Germany and in this country have shown a quite 
uniformly lower coefficient of digestibility for the pro- 
tein of the new process, than for the old process, meal. 
Woll tested this matter by artificial digestion with a 



248 • The Feeding of Animals 

solution of pepsin, and his results verified those se- 
cured with animals, the protein of the old process 
samples proving to be 10 per cent the more soluble. 
This difference is believed to be caused by the addi- 
tional cooking with steam which attends the driving 
out of the naphtha from the new process meal, for it 
seems to be well proven that the digestibility of vege- 
table protein is diminished by cooking. American 
experiments do not indicate a lower digestibility of 
total dry matter for the new process meal, which is 
contrary to the verdict of German digestion trials. 

The property of swelling to a mucilaginous condi- 
tion is one well known to pertain to flaxseed. This 
is due to mucilage cells found in the seed -coat. When 
this mucilaginous matter has once been swollen, it will 
not repeat the process after drying. Woll's tests 
showed that the old process meal responded to the 
swelling test, but not the new process, a result due 
probably to the steam cooking of the latter. This 
may serve as a means of determining the method used 
in manufacturing a given lot of meal, but probably has 
no special significance as to feeding value, unless it 
indicates the new process meal to be less useful in 
making a porridge for feeding calves 

CHEMICAL DISTINCTIONS IN CATTLE FOODS 

The classes of cattle foods as arranged in the pre- 
vious discussion have had reference to several factors, 
chiefly those relating to origin and texture. Chemical 
facts have not been considered in these divisious. There 



How Cattle Foods Differ 249 

are, however, certain chemical differences among the 
various groups of feeding stuffs, a knowledge of which is 
helpful in selecting materials for compounding rations. 

Coarse foods vs. grains and grain products. — In com- 
paring hays, straws, and other fodders with grains 
and grain products there are points of chemical un- 
likeness which bear an important relation to problems 
of nutrition. In the first place, the nitrogen com- 
pounds differ. In the grains we find the nitrogen 
combined mostly in the form of albuminoids, while in 
the fodders a proportion of it, and sometimes quite a 
large one, exists in amides. This is a point in favor 
of the grains, for, as we have seen, the nutritive 
function of amides is probably more limited than that 
of albuminoids. Again, the non -nitrogenous material 
of the grains is in general superior to that of the her- 
baceous cattle foods. In the former, especially in the 
cereal grains, there is but little fiber and the nitrogen- 
free extract is made up largely of starch and other 
bodies, whose net value in nourishing an animal is 
quite surely greater than that of fiber and gums found 
in such abundance in the hays and other fodders. 
The work of digesting fiber and gums is greater than 
with sugar or starch, and of the digested material from 
the former we cannot affirm an equal value with that 
coming from the more easily soluble carbohydrates. 
In short, the terms protein and nitrogen -free extract 
do not signify the same compounds or the same values 
when applied to different feeding stuffs. 

Classification according to the 2^oportions of nu- 
trients. — The relative proportion of nitrogenous and 



250 The Feeding of Animals 

non -nitrogenous compounds in feeding stuffs is greatly 
varied. There is no fixed proportion in the same spe- 
cies, even, but it varies to some extent with the season, 
period of cutting, and other conditions. At the same 
time, there are differences of composition between several 
groups of feeding stuffs that are constant within not 
very wide limits, and which it is important to recognize. 

There are a few terms that are popularly used to 
differentiate feeding stuffs which are misleading. For 
instance, corn meal is often spoken of as "carbona- 
ceous" in contrast to cottonseed meal, which is called 
"nitrogenous." It may be seen by reference to pre- 
ceding data that there is a higher proportion of carbon 
in albuminoids than in starch or sugars. Cottonseed 
meal is more carbonaceous than corn meal, rather than 
less so. Such a distinction is therefore absurd. 

"Heat forming" is another term often applied to 
foods rich in carbohydrates, while the more highly 
nitrogenous materials are characterized as "muscle 
forming," a distinction apparently based upon the facts 
that carbohydrates are usually largely burned in the 
animal body, and that albuminoids are the only source 
of the muscle compounds. But, as a matter of fact, 
the potential heat value of the digestible part of an 
oil meal is certainly as great as that of digestible 
corn meal. Under certain conditions one feeding stuff 
is no more fully, used than the other for tissue -forming 
purposes, and both may be wholly utilized in the pro- 
duction of some form of energy, ultimately heat, the 
potential value of the oil meal being no less in this 
respect than that of the corn meal. 



Classes of Feeding Stuffs 251 

The satisfactory division of feeding stuffs into as 
few as two classes, according to their composition, is 
not possible by the use of any terms whatever. Such 
a division is necessarily based upon the relation in 
quantity of the protein to the non- nitrogenous part, 
and there is an almost uniform gradation of foods in 
protein content from those containing the least to 
those most highly nitrogenous. Any division into 
groups with reference to the percentage amount of 
protein must be entirely arbitrary and should take 
account of at least four classes of materials, other- 
wise the extremes of each division are too widely 
apart. Probably no more convenient and rational class- 
ification of grains and grain products can be suggested 
than the one proposed by Lindsey: 

Class I. Thirty to 45 per cent protein, 30 to 45 per 
cent carbohydrates. The oil meals and gluten 
meals, the latter of which are represented by the 
Chicago, King, Cream, and Hammond. 
Class II. Twenty to 30 per cent of protein, 60 to 
70 per cent carbohydrates. Gluten feeds, in- 
cluding the Buffalo, Golden, Diamond, Daven- 
port, Climax, Joliet, and Standard as now 
made, Atlas meal, dried brewer's grains, malt 
sprouts, buckwheat middlings, and beans and 
peas. 
Class III. Fourteen to 20 per cent protein, 70 to 75 
per cent carbohydrates. Wheat brans and mid- 
dlings, rye bran, mixed feeds or any mixtures 
of oat feed reinforced by more highly nitrog- 
enous material. 



252 The Feeding of Animals 

Class IV. Eight to 14 per cent protein, 75 to 85 
per cent carbohydrates. Barley, corn, oats, rye, 
wheat, cerealine, hominy, oat feeds, corn and 
oat chop, and corn bran. The hays and other 
fodders properly belong with Class IV. 

By reference to these groups it is possible to ascer- 
tain about what place a particular feeding stuff will 
take in making up a ration, for instance, to what ex- 
tent it will serve as a protein amendment to a mixture 
of materials composed largely of carbohydrates. 

FOODS OF ANIMAL ORIGIN 

The principal materials of animal origin that are 
used in feeding domestic animals are milk, dairy by- 
products and offals from slaughter-houses. They are 
mostly characterized by their large relative proportion 
of protein and their high rate of digestibility. The 
net nutritive value of their solid matter is very high, 
because it is practically all utilized and a minimum 
amount of energy is required for its mastication and 
digestion. Practice has long recognized the peculiar 
efficiency of feeding stuffs of this class, which is due 
to the directs available forms of the nutrients. 

Milk. — Whole milk has a greatly varying food value 
according to its proportion of solid matter. Its com- 
position is determined by several factors. The milks 
of different species of domestic animals are greatly 
unlike both in their proportions of total solids and in 
the relation in quantity of the different constituents. 

The table of composition of the milk of several 



Milk of Various Species 253 

species, including human milk, given herewith, is taken 
mostly from figures given in Richmond's Dairy Chem- 
istry : 

Composition of the milk of mammals (per cent) 

Species Water Dry matter Ash Casein Albumin Sugar Fat 

Bitch 75.44 24.54 .73 6.10 5.05 3.09 9.57 

Ewe 79.46 20.56 .97 5.23 1.45 4.28 8.63 

Sow 84.04 15.96 1.05 7.23 3.13 4.55 

Goat 86.04 13.96 .76 3.49 .86 4.22 4.63 

Cow*.. 87.10 12.90 .70 3.20 5.10 3.90 

Woman 88.20 11.80 .20 1. .50 6.80 3.30 

Mare 89.80 10.20 .30 1.84 6.89 1.17 

The milks are arranged in the order of their rich- 
ness, the dry matter present varying from 24.54 per 
cent to 10.20 per cent. Those containing a high pro- 
portion of total solids, particularly those from the 
bitch and the ewe, are especially rich in proteids and 
fat, the percentages of sugar being less than half those 
in the poorer milks. It is noteworthy that the pro- 
portions of proteids and fats in the milk decrease, and 
the percentage of sugar increases, as the total solids 
diminish. Two -thirds of the solids of mare's milk is 
sugar, the proportion of this constituent in the dry 
matter of a ewe's milk being only about one -eighth. 

If we assume that the milk of each species is best 
adapted to its own progeny, it follows that when the 
young of other species is fed the milk of the cow, as 
is so often done, this milk should be modified so far 
as possible to simulate that provided under natural 
conditions. When, for instance, cow's milk is fed to 

* Van Slyke. 



254 ' The Feeding of Animals 

a colt, it should be diluted and have its content of 
milk sugar increased; or when lambs are given cow's 
milk it may well be made richer, by the addition of 
cream, perhaps. The milk of the cow varies with the 
breed, the individual and the period of lactation, and 
in its use for feeding purposes these variations should 
be considered. While we have little or no data on 
the subject, it is probable that the same causes op- 
erate in affecting the milk of all species. 

Dairy by-products. — These by-products are three 
in number, skim -milk both from the gravity and the 
separator processes, buttermilk, and whey. Their aver- 
age composition, as taken from compilations by several 
authors, is as follows: 

Composition of dairy offals (per cent) 

Total Casein and 

Water solids Ash albumin Sugar Fat 

Skim-milk, general average, Cooke... 90.25 9.75 .80 3.50 5.15 .30 

Skim-milk, gravity, Fleischman 89.85 10.15 .77 4.03 4.60 .75 

Separator-milk, Richmond 90.50 9.50 .78 3.57 4.95 .10 

Buttermilk, Cooke 90.50 9.50 .70 3. 5.30* .50 

Buttermilk, Vieth 90.39 9.61 .75 3.60 4.06t .50 

Whey, Cooke 92.97 7.03 .60 .93 5. .50 

"-They, Van Slyke 93.07 6.93 .60t .83 5.16 .34 

Skim -milk and buttermilk are not greatly unlike 
in richness in solid matter or in general composition. 
In case the skim -milk is sweet, buttermilk differs 
from it because in the latter the sugar has changed 
partially or wholly to lactic acid. Whey is considera- 
bly poorer in solids than the other dairy by-products 
and also differs from them in the proportions of the 
several constituents. 

* Probably includes the lactic acid, t.80 per cent lactic also present, t Assumed. 



Dairy By-products as Foods 255 

Skim -milk is the residue left after removing the 
cream. It differs in composition according to the 
composition of the original whole milk and the thor- 
oughness of the creaming. The percentage of solids 
which it contains is proportional in a general way to 
the richness of the whole milk. At one time a con- 
trary notion prevailed and the skimmed milk of the 
butter breeds, especially the Jersey and the Guernsey 
cows, was popularly supposed to be of inferior quality. 
Numerous analyses have been made of this by-product 
from several breeds, and the succeeding figures give 
the proportion of solids and fat in skimmed milk from 
the gravity process: 

Skimmed milk 
Solids in Total 

whole milk solids Fat 

% % % 

Holstein 12.22 9.50 .52 

Ayrshire 12.98 10.40 .85 

Jersey 15.24 10.50 .37 

These figures show most clearly that the Jersey 
product is more valuable than that from Holstein cows, 
volume for volume. 

Skim -milk is also affected by the manner or thor- 
oughness with which the cream is removed. The more 
perfectly the fat is taken out the less the percentage 
of solids left behind and the less their unit value as 
a source of energy. For these reasons gravity process 
skimmed milk is often more valuable for feeding than 
that from the separator, though under the best con- 
ditions of skimming in both cases the difference is 
small. 

Buttermilk, which is the residue after extracting 



256 . The Feeding of Animals 

butter from cream, varies in composition from such 
causes as the composition of the cream and the per- 
fectness of the churning. The more fat is left in it 
the more it is worth for feeding purposes. Its feeding 
value is but little less than that of skim -milk. 

Whey solids are mostly sugar. In good cheese- 
making practice, whey retains scarcely any of the 
casein and fat of the milk. It therefore takes a place 
in the ration quite different from that of skim -milk, 
as it is essentially a carbohydrate food. 

The dairy offals are peculiarly valuable as food 
for young animals and swine. It is safe to say that 
for calves and pigs no other sufficiently inexpensive 
materials can fully take their place in their relation 
to health and vigor. 

Slaughter-house and other animal refuses. — The 
offals from slaughter-houses and from fish, which 
have a somewhat limited use in feeding domestic ani- 
mals, are meat scraps, meat meal, dried blood, and 
dried and ground fish. The accompanying analyses 
display their composition, which is subject to great 
variations : 

Composition of slaughter -house and other refuses {per cent) 

Water Ash Protein Fat 
Animal meal, N. Y. station. . 2.2 
Meat meal, German analysis. . 10.7 
Fish scrap, German analysis. 13.9 
Dried blood, Henry 8.5 

The meat and fish offals vary greatly according to 
proportion of bone which they contain. The percen- 
tage of protein is always large, nevertheless. Dried 



38.7 


37.5 


13.2 


4.1 


71.2 


13.7 


31.3 


48.4 


6.4 


4.7 


84.4 


2.5 



Feeding Stuffs of Animal Origin 257 

blood is much less rich in mineral matter and fat 
than other slaughter-house offals are generally, and 
the proportion of protein is correspondingly larger. 
All these materials are excellent poultry foods when 
used as a part of the ration. They may be fed to 
swine also as an amendment to cereal grains when 
dairy by-products are not available. 



Q 



CHAPTER XVII 

THE PRODUCTION OF CATTLE FOODS 

The farmer, in deciding what forage and grain 
crops he shall grow, should take into consideration 
several factors, of which the following are the main 
ones: (1) the adaptability of the various crops to the 
soil and climate; (2) the adaptability of the various 
crops to the kind of business which is to be followed, 
whether dairying, stock- growing or sheep husbandry; 
(3) the capacity of the various crops for the produc- 
tion of digestible food; (4) the protein supply; (5) 
the maintenance of fertility. 

1. Concerning the adaptability of crops to the great 
variation of soil and climate in this country, it is not 
possible to treat extensively in this connection without 
going too fully into questions of agricultural botany. 
There are, however, a few general facts worthy of men- 
tion. In the first place, few farmers have accurate 
information concerning the species of grasses w T hich 
are growing on their farms. Only occasionally is one 
found who carefully observes what species are most 
prosperous under his conditions. This is equivalent 
to the statement that but little attention is given to 
the matter of the adaptability of forage plants to the 
environment under which they must be grown. While 

(258) 



The Selection of Crops 259 

it may be said that nature carries on for the farmer 
more or less of a selective process, it must be remem- 
bered that the rotation of crops, involving of necessity 
an artificial selection of species, interferes with this 
process. The old practice of maintaining mowing 
fields for ten to twenty years without breaking the sod 
might allow the grasses most congenial to the soil and 
climate to establish themselves, but successful farming 
on this basis is now scarcely possible. It is essen- 
tial, therefore, especially in dealing with meadows and 
pastures, to know what members of the grass family 
or other forage plants find the environment congenial. 

It is commonly remarked, with much reas6n, that 
more is to be gained by the proper selection and proper 
care of the forage crops which have maintained suc- 
cessful, though perhaps unrecognized, existence among 
us for years, than by seeking for better results from 
some introduced species. No cultivated plant pos- 
sesses qualities that will defend the farmer against the 
evil effects of poor or ill-directed culture, and when 
intelligent, thorough methods prevail, many of the 
familiar species will do for us all we can reasonably 
expect. Occasionally an introduced species may serve 
a useful purpose, as is true of alfalfa, but in general a 
more economical production of cattle foods will be 
reached most surely through an improvement of meth- 
ods in growing what we already have. 

2. It is obvious that the home production of feed- 
ing stuffs must be adapted to the kind of stock kept. 
A herd of good dairy cows can hardly be most suc- 
cessfully managed on the old basis of exclusive pastur- 



260 The Feeding of Animals 

ing in the summer and exclusive dry food in the 
winter. To attain the best results the pasture must 
be amended by soiling crops, at least during late sum- 
mer and early autumn, and a succulent food is a de- 
cided improvement to a winter ration. On the other 
hand, the successful growing of steers, sheep or horses 
requires in many localities only a good pasture and 
plenty of dried fodder and grain, although some suc- 
culent foods are desirable with any class of animals. 
Every feeder, no matter what his line of business, 
should have at command quite a variety of fodders. 

3. The productive capacity of the different crops 
used as cattle foods is greatly unlike. A satisfactory 
crop of maize or alfalfa contains greatly more dry 
matter per acre than one of oats, peas, or any of the 
usual meadow grasses, and in order that land may 
yield a maximum supply of feeding stuffs it is neces- 
sary to step outside grass and grain farming, where 
long rotations are practiced and where a major part of 
the farm is kept in meadow grasses and only small 
areas are devoted to cultivated crops. Rapid rota- 
tion and the use of the more grossly feeding crops 
are necessary to a vigorous development of the re- 
sources of any land for the maintenance of animal 
husbandry. 

Other things being equal, the most desirable crop 
is the one producing the largest amount of digestible 
dry matter. This will not be the same crop for all 
localities. In one section it may be maize, in another 
alfalfa, or in another roots. The selection must be 
determined by circumstances, and no rule of general 



Productive Capacity of Different Crops 2G1 

application is possible. Of course, other things out- 
side of quantity of production are not generally equal. 
The cost of production varies so that the largest yield- 
ing crop is not necessarily the most economical. This 
is a local matter also, concerning which no safe gen- 
eral statement can be made. It would be convenient 
if some correct, universal standards of production and 
cost could be formulated for the guidance of farmers, 
but both growth and cost are much modified by lo- 
cality and other circumstances, and data are not avail- 
able, and doubtless never will be, from which useful 
averages may be obtained. 

The most that it is possible to show is the rela- 
tive productive capacity of different crops when the 
yield is what is regarded as highly satisfactory in fa- 
vorable localities under good culture. This is done in 
the accompanying table. Attention is again called 
to the fact that judgment should be based upon the 
amount of digestible dry matter produced : 

Dry Digestible 

Yield Dry mat- dry 

per acre matter ter matter 

fresh ma- Dry per digesti- per 

terial matter acre ble acre 

lbs. $ lbs. <f> lbs. 

Alfalfa 35,000 25 8,750 69 5,162 

Maize, whole plant 30,000 25 7,500 61 5,025 

Red clover, about 3% tons new hay.. 18,000 30 5,400 57 3,070 

Oats and peas 20,000 16.2 3,240 65 2,106 

Timothy, about 2% tons new hay.... 11,500 38.4 4,416 57 2,517 

Hungarian grass 19,000 25 4,750 67 3,182 

Mangolds 60,000 10 6,000 88 5,200 

Sugar beets 32,000 20 6,400 88 5,632 

Potatoes 18,000 25 4,500 85 3,825 

The estimates here given may not coincide with the 
views of all as to what constitutes a fair crop, but 



262 The Feeding of Animals 

from the data shown, any one can easily make a cal- 
culation on the basis of his own estimate. 

The foregoing figures emphasize the relative high 
productivity of alfalfa, maize and roots, as compared 
with certain cereal grains and the meadow grasses. 
The former crops fill an important place in intensive 
stock husbandr}'. Probably no species of forage plants 
are known that are more economical sources of high class 
cattle food than alfalfa and maize. While no more 
productive than mangolds and sugar beets when these 
are at their best, the former cost much less in labor. 

Crops of such large productive capacity are espe- 
cially adapted to dairymen located on limited areas of 
high-priced land. They occupy a place in intensive 
culture which will become more and more important 
as grazing and long rotations are replaced by soiling 
and stable feeding during the entire year. 

4. The protein supply of the farm may be aug- 
mented by the growth of leguminous crops, such as 
peas, beans, alfalfa and the clovers. In so far as climate 
and soil permit the economical production of this class 
of fodders, there will be a correspondingly less neces- 
sity for the purchase of nitrogenous feeding stuffs. 

5. The leguminous crops are regarded as sustaining 
an important relation to fertility in acting as nitrogen- 
gatherers, and for this reason they are believed to be 
a valuable adjunct of any system of farming. Just 
what proportion of the nitrogen in a crop of clover, 
for instance, comes from outside the soil is not known, 
however, either for particular conditions or as to the 
average . 



Importance of Soiling Crops 26'S 

SOILING CROPS 

The production of green crops as an amendment to 
the pasture, or as a substitute for it, is a practice essen- 
tial to the highest success in dairyiug on many farms, 
and is to some extent desirable in other branches of 
stock husbandry. 

There are few pastures, perhaps none, that afford 
grazing in August and September of such a quality as 
to maintain a satisf acton 7 flow of milk. In many 
instances, moreover, farmers owning a limited area of 
high-priced tillable land wish to keep the maximum 
number of animals per acre, and to do this they must 
cultivate soiling crops for stable feeding. 

It is no longer a debatable question, whether or not 
soiling is profitable under most conditions. Unlimited 
testimony can be furnished showing the great gain 
from every point of view of even partial soiling as an 
amendment to the pasture. Whether soiling should be 
substituted entirely for grazing is a business matter 
which should be decided according to the conditions 
involved. 

New England farmers owning upland rocky pas- 
tures in which grow native grasses of the highest 
quality for any class of animals could not wisely dis- 
card them. Such land generally absorbs but little cap- 
ital, and the labor of supplying food by this method 
is reduced to a minimum. The case is different with 
high-priced, easily tilled land located near good mar- 
kets. These conditions call for intensive farming, and 
grazing animals on permanent pastures is not a part 



264 • The Feeding of Animals 

of intensive practice. Under such circumstances the 
wisdom of a soiling system is clearly indicated. 

In the first place, much more food is produced per 
unit of area by soiling than by pasturage. Armsby 
found that two soiling crops in one season, for instance, 
rye followed by corn, yielded five times as much diges- 
tible organic matter as pasture sod, when the whole 
growth on the latter was plucked without waste, the 
quantities being, respectively, 5,845 pounds and 1,125 
pounds. It is variously estimated from observations 
in practice, that three to five times as many animals 
can be supported on a given area by soiling as by 
grazing. 

Again, grazing is wasteful because of the imperfect 
consumption of the growth that is made. Much grass 
is tramped down and much is fouled with dung and 
urine. These facts are well understood. Other advan- 
tages besides economy of land and material pertain to 
soiling, such as saving of fences, comfort of the ani- 
mals and an increased supply of manure, but these 
factors do not require discussion in this connection. 

Outside of considerations previously noted, produc- 
tiveness especially, the dairy farmer in selecting soiling 
crops must have regard chiefl}' to the number of ani- 
mals to be fed, the time when the crops will be needed, 
and the number of days required for their develop- 
ment. If soiling is adopted in order to amend the 
pasture during the late summer and early fall a lim- 
ited number of crops will meet the demand. Three 
sowings of peas and oats in late May and early June 
and two plantings of corn, one at the usual time and 



Kinds and Succession of Soiling Crops 265 



one two weeks later, would furnish a supply of green 
food when it is most likely to be needed. If it is a 
question of selecting crops for a system of complete 
soiling, nothing more suggestive can be offered as 
to species and succession than schemes prepared by 
Phelps for Connecticut, and by Voorhees for New 
Jersey : 

Connecticut scheme 

Approximate 
Species of crop Time of seeding time of feeding 

Winter rye Sept. 1 May 10-20 

Winter wheat Sept. 5-10 May 20- June 5 

Clover July 20-30 June 5-15 

Grass (from meadows) June 15-25 

Oats and peas April 10 June 25-July 10 

Oats and peas April 20 July 10-20 

Oats and peas April 30 July 20-Aug. 1 

Hungarian June 1 Aug. 1-10 

Clover, rowen Aug. 10-10 

Soy beans May 25 Aug. 20-Sept. 5 

Cow peas June 5-10 Sept. 5-20 

Rowen grass (meadows)-. Sept. 20-30 

Barley and peas Aug. 5-10 Oct. 1-30 

New Jersey scheme 

Approximate 
Species of crop Time of seeding time of feeding 

Winter rye Sept. May 1-10 

Winter wheat Sept. May 10-20 

Crimson clover Sept. May 20 June 1 

Oats and peas April 1 June 1-10 

Oats and peas April 10 June 10-20 

Mixed grasses Sept. June 20-30 

Oats and peas May 10 July 1-10 

Cow peas May 20 July 10-20 

Corn June 1 July 20-Aug. 1 

Japanese millet June 20 Aug. 1-10 



266 The Feeding of Animals 

New Jersey scheme — continued 

Approximate 
Species of crop Time of seeding time of feeding 

Cow peas June 10 Aug. 10-20 

Corn June 20 Aug. 20-Sept. 1 

Soy beans July 10 Sept. 1-10 

Japanese millet July 20 Sept. 10-20 

Corn July 1 Sept. 20-Oct. 10 

Barley and peas Aug. 10 Oct. 10-20 

Barley and peas Aug. 20 Oct. 20-30 

The schemes are not practicable for all sections of 
the United States. In the southern and western states 
more especially, they would need modification to suit 
local conditions. 

Alfalfa is not included in either of the foregoing 
lists. For all sections where this plant can be grown 
successfully it takes first rank as a soiling crop. In 
portions of New York, for instance, in favorable sea- 
sons it can be cut continuously from about the middle 
of May until late in September, and no other crop is 
more thoroughly relished by horses and cattle. It is 
valuable for horses, even when they are doing hard 
work. 

The area devoted to soiling crops must be deter- 
mined by the number of animals and the productive- 
ness of the land which is to be used. Voorhees states 
that seven acres devoted to the succession of crops 
which he recommends will supply twenty* -five cows 
from May 1 to November 1. This estimate would 
hold only when two and three crops are grown on the 
same land in a single season, which requires a generous 
use of manure or of commercial fertilizers, or of both. 
The following are suggestions of possible rotations: 



Rotations of Soiling Crops 



267 



{Winter rye, or crimson clover 
Oats and peas 
Soy beans 

{Oats and peas 
Japanese millet 
Barley and peas 
J Winter rye, or winter wheat 
(Corn 



{Winter wheat 
Cow peas 
Japanese millet 

{Oats and peas 
Cow peas 
Barley and peas 

Crimson clover 
Corn 



Some writers estimate the needed area of soiling 
crops on the basis of one -quarter to one -half a square 
rod per day for each full-grown animal, the smaller 
unit applying to corn and the larger to oats and peas, 
and similar crops. All this must be a matter of judg- 
ment based upon the circumstances involved. 



CHAPTER XVIII 
THE VALUATION OF FEEDING STUFFS 

It seems to be very generally supposed that it is 
possible to state fixed relative money values for feed- 
ing stuffs, and that by comparing these with market 
prices the relation of value to cost may be ascertained. 
Such a state of knowledge is certainly much to be de- 
sired, for it would be of great practical use to feeders. 
For various reasons, however, it is not yet attained, 
and there is little present prospect that it will be. 
The establishment of such relative values for cattle 
foods, as a whole and for general use, is a much more 
complex matter than many suppose it to be, for it 
touches on one side some of the most profound prob- 
lems of physiological chemistry, concerning which we 
have only partial knowledge. 

The problem of assigning values to the classes of 
nutrients in feeding stuffs may be approached from 
two directions; viz., from the commercial side and 
from the physiological side. In the first case, the 
effort would be to calculate on the basis of the prices 
of standard commercial feeds, what is the actual pound 
cost of each of the classes of nutrients, and thus have 
a means of ascertaining whether a particular «feed is 
selling for less or more than the existing market con- 

(268) 



Calculating Values of Feeding Stuffs 269 

ditions warrant. In the second case, the attempt would 
be to determine the relative physiological importance 
of digestible protein, carbohydrates, and fats, and this 
being done, the relative agricultural values of feeding 
stuffs would be established on the basis of their com- 
position and digestibility, thus providing purchasers 
with a guide for selecting the materials costing the 
least in proportion to their value. 

COMMERCIAL VALUES 

Experiment stations have for many years published 
relative commercial valuations of the various brands 
of fertilizers that are in the market. Why are we not 
able to follow the same course with cattle foods ? Sim- 
ply because of existing conditions. The dry matter of 
cattle foods is made up of ash, protein, carbohydrates, 
and fats. We practically ignore the ash and base the 
value of a given food upon the other three classes of 
compounds, which are the same in number as the three 
useful ingredients of mixed fertilizers. Now if we 
could find in the market a cattle food supplying only 
a single ingredient, as is the case with fertilizers, we 
could from its composition and market price determine 
the cost of this ingredient. As a rule, however, these 
classes of nutrients must be bought in a mixed condi- 
tion. All commercial cattle foods, except, perhaps, 
one waste product from sugar production, are mix- 
tures in varying proportions of protein, carbohydrates, 
and fats. When we buy one we buy all three. Pro- 
tein, starch, sugar or oils as found in commerce have 



270 The Feeding of Animals 

become, through the necessary processes of separation, 
too costly to be considered for cattle -feeding purposes, 
and their prices in these forms are not a proper 
basis of calculation. If, therefore, a farmer pays $15 
for a ton of wheat bran, what proportion of this sum 
shall he assign to the 320 pounds of protein, the 
1,240 pounds of carbohydrates, or the 84 pounds of 
fats? 

Commercially considered our problem is complex, 
and no simple process will solve it. If we were to 
determine what is the cost of one pound of dry matter 
through the simple division of the price of a ton of 
feed by the pounds of dry matter which it contains, 
and then declare that all forms of dry matter have 
equal cost, we would get as many prices for protein 
and starch as there are commercial feeds, with no dis- 
tinction as to the money value of these nutrients. 
Such a method would be absurd. It would be a bare 
assumption to declare that all the compounds of a 
food should have equal market cost. 

An attempt was made in Germany, and to some 
extent in this country, to calculate by the "method of 
least squares " what should be considered the cost of 
protein, carbohydrates, and fats as based upon the 
ton prices of a variety of feeding stuffs. Valuations 
so derived appeared to find favor for a time, and some 
of our experiment stations, following the lead of Ger- 
man chemists, published pound prices for the three 
classes of nutrients, and calculated what commercial 
cattle foods should cost when valued on a common 
basis. It was soon found, however, that, mathemati- 



Inaccuracies of Money Valuations 271 

cally as well as practically, most absurd results were 
obtained. 

In the first place, it is already demonstrated that 
the money valuations are often greatly influenced by 
the choice of feeds which shall enter into the calcula- 
tion. Penny, in New Jersey, using cottonseed meal, 
bran, middlings, cobmeal, corn meal, and oats, ob- 
tained certain values for protein, carbohydrates, and 
fats. Hill shows that if Penny had left out the cob- 
meal the value for fat would be only half that found, 
and the value of the protein and carbohydrates would 
be a quarter more. Woll obtained certain pound prices 
with a list of common feeds, but Hill shows again 
that if Woll had left out rye bran these prices would 
be greatly changed. It appears that varying individual 
judgments as to the list of feeds which shall determine 
values maj' cause absurd differences in the calculated 
market cost of the nutrients, and introducing into the 
list or withdrawing from it a comparatively unim- 
portant feeding stuff may lower or raise the price of 
one nutrient even one -half. 

A still more serious difficulty arises from the fact 
that often when an apparently typical and proper list 
of feeds is used from which to calculate prices, the 
use of the method of least squares results in giving 
a negative value to one of the nutrients. In several 
cases of this kind the fat was shown to be worth less 
than nothing, a most absurd conclusion. This mathe- 
matical method is, therefore, not available for the 
valuation of feeding stuffs, and so far no mathema- 
tician has offered one that is. 



272 The Feeding of Animals 

PHYSIOLOGICAL VALUES 

We are left now to inquire whether we ma}' not 
use physiological values, in other words the work which 
a nutrient will perform in the animal body, as a start- 
ing point from which to calculate relative values. If, 
for instance, it could be demonstrated that protein has 
a fixed physiological value twice, and fats three times, 
that of carbohydrates, it would then be a very simple 
matter to ascertain what proportion of the cost of a 
ton of cottonseed meal should be applied to each class 
of nutrients. To illustrate, a ton of average cotton- 
seed meal contains about 590 pounds of carbohydrates, 
860 pounds of protein, and 260 pounds of fat. If 
these ingredients are assumed to have a ratio of value 
of 1, 2, and 3, then the whole would be equivalent to 
3,090 units of carbohydrates, the cost of one unit of 
which would be .8 cent, when we pay $25 per ton 
for the cottonseed meal. On this basis it would be 
necessary to assign to the protein a cost of 1.6 cents 
per pound, and to the fats 2.4 cents. If our premise 
were correct we could calculate the cost of the nutrients 
in any one of the feeding stuffs, and could either 
ascertain which was the cheapest source of each in- 
gredient, or by averaging could establish a basis for 
a general valuation. Unfortunately no such a premise 
can be correctly formulated. We are not yet wise 
enough to establish fixed relative physiological values 
for the three classes of nutrients. 

It may be asked, do we not know the heat value of 
a unit of each of the nutrients, of protein, of starch, 



Physiological Values not Definite 273 

and of fat ? We probably do. These values have 
been found with apparent accuracy. Why, then, may 
we not establish the relative, value of the nutrients 
on the basis of their potential energy, which is meas- 
ured by the heat they produce upon combustion ? Sim- 
ply because foods have another function beside fur- 
nishing motive power to the animal and keeping 
him warm. They act as building material. The pro- 
tein and fat of milk and of the body tissues are de- 
rived from the food compounds, and the actual rela- 
tive value of these compounds for constructive pur- 
poses is not yet known. No one has yet succeeded in 
actually determining the relative money value of pro- 
tein, carbohydrates and vegetable fats as fat producers, 
and we have no data that allow a definite conclusion 
concerning the comparative money worth of the muscle- 
forming function of protein as against the fat -forming 
function of starch. There is no promising prospect, at 
present, of being able to compare foods on the basis 
of their physiological importance as a means of deter- 
mining what should be the relative market cost. 

SELECTION OF FEEDING STUFFS 

What useful knowledge is available to the stock- 
feeder as a means of guiding him to an economical 
selection ? In the first place, the feeder may know 
the composition of feeding stuffs. If he cares to be 
intelligent in his business he will know that some 
feeds carry more nitrogenous matter than others; he 
will be aware that all the cereal grains contribute to 

R 



274 The Feeding of Animals 

the ration much the same compounds in much the 
same proportions, and he will understand the varia- 
tions of composition among the waste products that 
are in the market as commercial feeds. He will learn 
how the coarse foods differ among themselves and 
from the grains. Practice and observation will teach 
him that some feeds are better adapted than others to 
a certain class of animals, even though of essentially 
the same composition. In his efforts to compound 
rations he will not only have regard for this adapta- 
tion, but he will keep in mind what practice and sci- 
ence have taught concerning the mixtures necessary 
to secure an efficient combination of nutrients for the 
work to be done. 

After all this is understood, there may be several 
feeds which are essentially alike in composition and 
nutritive function but which have different prices, and 
there still remains the problem of selecting the most 
economical. If a feeder wishes for carbohydrates, 
from what source should he purchase them ? If he 
needs protein should he select gluten meal, one of 
the oil meals, or some other of the nitrogenous by- 
products ! It is clear that the best he can do is to 
select the feeds that supply the largest quantity of 
available nutrients for the least money. If all the 
feeding stuffs were digested in equal proportions there 
would be no need of considering digestibility, but this 
is not the case. Large differences in digestibility exist. 
From 86 to 88 per cent of the dry matter of the 
cereal grains, oats excepted, is dissolved by the diges- 
tive juices, while the solubility of wheat bran, brewer's 



Selecting Feeding Stuffs 275 

grains, and oat feeds is on the average only about 62 
per cent. Oats are nearly one -fourth less digestible 
than corn, barle} r or rye. The refuse products known 
as the oil meals are less digestible than the gluten 
feeds and meals, due, doubtless, to the hulls contained 
in the former. These facts are important and affect 
the nutritive value of commercial feeds very materially. 
Farmers should base their judgment of the value 
of feeding stuffs primarily upon the proportions of 
digestible dry matter which they contain. This method 
will probably allow the closest approximation to rela- 
tive values of any. It is certainly more accurate than 
a comparison of the proportions of total dry matter. 
A hundred pounds of corn contains even less dry 
matter than the same weight of oat feed, but the di- 
gestible material of the former is over 30 per cent in 
excess of that in the latter. It is to be remembered, 
however, that comparisons of this kind can only be 
instituted between feeding stuffs of the same class. 
The relative values of oil meal and corn meal cannot 
be ascertained in this way, neither can those of tim- 
othy hay and corn meal. We should not pay for oil 
meal and corn meal on the basis of the quantities of 
digestible nutrients w T hich they furnish, because the 
nutrients are not identical in the two cases. Diges- 
tible material, which is 40 per cent protein, cannot be 
measured by digestible material, which is only 10 per 
cent protein. Neither can we so compare timothy hay 
and corn meal, for while the proportions of protein 
and non- protein compounds may not be so very differ- 
ent in the two, the nitrogen -free compounds are 



276 



The Feeding of Animals 



greatly unlike and may have unlike physiological 
values, as we have seen. 

The following table shows the digestible material 
in 100 pounds of various feeding stuffs, as calculated 
from average composition and digestibility. In the 
case of hays the water content is assumed to be uni- 
form; viz., 12.5 per cent, while the percentages given 
for the grains are the averages found by analysis: 



Class I— Dried grass plants 

Corn fodder, dent 

Corn fodder, flint, , 

Corn fodder, sweet , 

Corn stover 

Hungarian hay 

Oat straw , 

Orchard grass hay 

Red top hay , 

Timothy, all 

Timothy, in bloom or before 
Timothy, after bloom 

Class II— Dried legumes 

Alfalfa 

Clover, alsike 

Clover, red 

Clover, white , 

Class III— Cereal grains 

Barley 

Corn meal 

Corn and cob meal 

Oats 

Oat feed 

Rye meal 



Per cent of 

digestibility 

of dry 

matter 

64 

68 

67 

57 

65 

50 

57 

60 

53 

61 

53 

59 

58 
57 
67 

86 
88 
79 
70 
62 
87 



Pounds dry 
matter in 
100 of the 

feeding stuff 

60* 
60* 
60* 
60* 

87.5 

90 

87.5 

87.5 

87.5 

87.5 

87.5 

87.5 
87.5 
87.5 
87.5 

89 
85 
85 
89 
92 
88 



Pounds 

digestible 

dry matter 

in 100 of 

feeding stuff 

38.4 

40.8 

40.2 

34.2 

56.9 

45 

49.9 

52.5 

46.4 

53.4 

46.4 

51.6 
50.8 
49.9 
58.6 

76.5. 

74.8 

67.1 

62.3 

57 

76.5 



*Assumed. 



Selecting Feeding Stuffs 277 

Pounds 

Per cent of Pounds dry digestible 

digestibility matter in dry matter 

of dry 100 of the in 100 of 

matter feeding stuff feeding stuff 
Class IV— Nitrogenous feeds 
16-30 per cent protein 

Brewer's grains 62 92 57 

Gluten feed 86 92 79.1 

Malt sprouts 67 90 60.3 

Wheat bran 62 88 54.5 

Wheat middlings 75 88 66 

Pea meal 87 90 78.3 

Class V— Nitrogenous feeds 
30-45 per cent protein 

Gluten meal 90 92 82.8 

Linseed meal, O. P 79 91 71.9 

Linseed meal, N. P 80 90 72 

Cottonseed meal 74 92 68 

It is fully recognized that these figures cannot be 
taken as absolute relative values. Feeding stuffs bear- 
ing the same name are not always exactly similar in 
composition or in equally good condition. Variations 
in the moisture content occur, especially with the coarse 
fodders. Even after allowing for all these factors, 
results will not follow exactly the quantities of diges- 
tible matter supplied, because there seems to be a 
greater adaptability of some feeds to the needs of a 
particular species. Nevertheless we are forced to con- 
clude that food materials of the same class must fur- 
nish energy and building material in proportion to 
what is digested from them. 

OTHER STANDARDS OF VALUATION 

Certain writers and speakers base the value of ni- 
trogenous feeding stuffs, from bran up, entirely on the 



278 The Feeding of Animals 

protein content, and they divide the price by the 
pounds of protein in a ton in order to determine the 
relative economy of purchasing this or that material, 
and the feeding stuff in which the protein cost is the 
least when so reckoned is regarded as the economical 
one to purchase. This method seems to be absurd, for 
it is an assumption that the nutritive value of the 
carbohydrates and fat in commercial foods may be 
ignored. The argument is that the farm furnishes 
carbohydrates in abundance, and that commercial 
products should merely serve the purpose of rein- 
forcing the protein supply. If the carbohydrates of 
the farm have no selling value then this argument 
has some force, but this is ordinarily not the case. 
When starch and similar compounds must be pur- 
chased as a necessary accompaniment of protein, thus 
causing a surplus of carbohydrate food, certainly hay, 
oats, corn, barley, or some other home product may be 
sold to relieve this surplus. 

Many practical feeding experiments have been con- 
ducted for the purpose of comparing the different 
grain products as foods for the various classes of 
animals. Useful facts have been reached in this way, 
especially as the greater adaptability of some materials 
than others for a particular species. But experiments of 
this kind cannot be relied upon to fix relative values of 
feeding stuffs for milk production, beef production or for 
any other purpose. This is so, first of all, because the 
errors of such tests are so large that we cannot re- 
gard their apparent outcome as establishing constants. 
Again, the problems involved are too complex and the 



Inaccurate Standards of Valuation 279 

effect of a given ration too dependent upon variable 
conditions, to allow logical conclusions from such ex- 
perimental data. The difficulties of the situation 
will be made clear to any one by a careful study 
of the whole mass of data resulting from feeding 
tests. Differences appear, some of which are consist- 
ently in one direction, especially in comparing nitrog- 
enous with carbohydrate foods, but as between mate- 
rials of the same class their comparative values as 
indicated bj r different experiments are greatly variable, 
even contradictory. Any one who endeavors to reach 
fixed and universal valuations on an experimental 
basis of this kind will find himself involved in hope- 
less confusion. 

Once in a while some one talks wildly about leaving 
food valuation to the "old cow." It is sometimes con- 
sidered a telling argument against the chemist's wis- 
dom to declare that he and the old cow do not agree. 
Certainly the cow knows better than the chemist what 
she likes to eat, and it is little use to offer her foods 
she does not relish. Even a chemist knows that. If, 
however, a dozen commercial feeding stuffs were spread 
around on a barn floor it would be much safer to 
trust an agricultural chemist, especially one experi- 
enced in stock feeding, to select a ration than any 
cow ever grown, — Holstein, Ayrshire, Jersey, long- 
horned, dishorned, or what not. The cow would prob- 
ably get at the corn meal and stay with it until well on 
the way to a fatal case of indigestibility. Her judg- 
ment is just about as good as that of a child with a 
highly cultivated "sweet tooth." 



CHAPTER XIX 

THE SELECTION AND COMPOUNDING OF RATIONS 

There are several factors that must be considered 
in selecting an efficient and economical ration, — factors 
which relate to both science and practice. It is gener- 
ally desirable that a food mixture shall be "balanced," 
but this gives, no assurance that a ration can be fed 
under particular conditions with satisfactory results. 
Intelligent observation in the barn or stable really 
takes the first place in formulating a method of feed- 
ing, which is supplemented to a valuable extent by the 
scientific insight of the chemist and physiologist. A 
ration may be chemically right and practically wrong, 
but, at the same time, it is worth much to the feeder 
to be assured that the nutrients which he supplies to 
his animals will meet their physiological ueeds. More- 
over, commercial relations such as the prices of feeds 
must be considered, and this is a business question 
and not a scientific matter. 

1. A successful ration must be palatable. An 
agreeable flavor is not a source of energy or of build- 
ing material, but it tends to stimulate the digestive 
and assimilative functions of the animal to their high- 
est efficiency, and is a requisite for the consumption 
of the necessary quantity of food. Common experience 

(280) 



Palatableness and Adaptability of Ration 281 

teaches that when cows or animals of any other class 
do not like their food, they "do not do well." Per- 
sons sometimes claim that they have contracted dys- 
pepsia by eating food which is not relished, even food 
that is nutritious and well cooked, and which would 
be entirely satisfactory to other individuals. The situ- 
ation is still worse when the food is undesirable both 
as to texture and flavor. We have reason to believe 
that animals are susceptible to the same influences as 
man, though perhaps not to the same extent. An ani- 
mal is more than a machine, and is possessed of a 
nervous organism, the existence of which should never 
be ignored. 

One way of stimulating an animal's appetite is to 
feed a variety of materials. Continuous feeding on a 
single coarse food and one grain is not conducive to 
the best results. The various available fodders and 
grains should be so combined as to allow the feeding 
of all of them throughout the season and avoid the 
exclusive use of one or two kinds for any extended 
period of time. The skilful feeder, then, will not fail 
to make the ration as palatable as possible, and will 
always consider the idiosyncrasies of appetite of each 
animal. 

2. The ration must be adapted to the species. This 
is obvious as relates to quantity, but is equally true of 
the kinds of materials. For instance, both poultry and 
swine generally eat cottonseed meal with reluctance 
and with danger to health. Wheat bran is less de- 
sirable for swine than for other species. The horse 
and the hog are not adapted to rough fodder as are 



282 The Feeding of Animals 

the ruminants. It is useless, however, to mention at 
this point other instances of this character, or to com- 
ment on their importance, further than to emphasize 
the foolishness of trying to bring all species of animals 
to a common basis in the supply of feeding stuffs. 

3. The physiological requirements of the animal 
must be considered. A ration of maximum physio- 
logical efficiency and economy must contain the several 
nutrients in such quantities and proportions as will 
meet the needs of the particular animal fed, without 
waste. This statement is based upon facts given else- 
where in this volume relative to the demands of the 
animal body- and the functions of the nutrients. 

It remains now for us to consider how to compound 
such rations as are desired, or those that are adapted 
in kind and quantity to the requirements which they 
are to meet. Obviously, the first essential for doing 
this is the adoption of standards to which rations 
should conform, for if we do not have these there is 
no possibility of concluding whether one food mixture 
is better or worse than another for a particular pur- 
pose. 

Such standards have been proposed, which we knew 
first as German feeding standards. As found in the 
tables published by German authors, they are the 
result of numerous and elaborate studies of the bal- 
ance of loss or gain to the animal organism when 
rations of various kinds were fed to animals at rest, 
at work, and when producing meat, wool or milk, in 
desirable quantities. They relate entirely to physio- 
logical demands without reference to the cost of the 



Feeding Standards 283 

rations or to the profits which may result from their 
use. 

These standards take account of two main factors: 
(l).the quantity of available nutrients, and (2) the 
relative proportions of the classes of nutrients. Quan- 
tity is an essential consideration, for it is obvious that 
enough energy and building material must be supplied 
to do a given work. It is also obvious that quantity 
must be a variable factor according as the animal is 
large or small, doing hard or light work, giving much 
or little milk, or fattening rapidly or slowly. 

Account must be made of the proportions of the 
nutrients, because protein, for instance, has peculiar 
functions which other nutrients cannot exercise, and 
less than a certain minimum of the proteids would 
limit production by just the amount of the deficiency. 
In order for the protein to serve its maximum useful- 
ness its energy should not be encroached upon to fill 
a place equally well or better taken by carbohydrates; 
consequently, the proportion of carbohydrates must also 
be considered. 

The relative proportion of the nutrients of a ration 
we speak of as the nutritive ratio. By this term is 
meant the relation in quantity of the digestible pro- 
tein to all the other digestible organic matter reck- 
oned in terms of carbohydrates. If we multiply the 
quantity of fat by 2.4 we get its carbohydrate equivalent, 
and if we add this product to the quantity of carbo- 
hydrates present as such we have the carbohydrate 
value of the digestible matter other than the protein. 
This sum divided by the number representing the pro- 



284 The Feeding of Animals 

tein gives the nutritive ratio. For instance, in a ration 
mentioned later there are .94 pound protein, 9.65 
pounds carbohydrates, and .49 pound fat. (.49X2.4 
-+- 9. 65)-h. 94 = 11.5. 1:11.5 is therefore the nutritive 
ratio of the ration. 

A nutritive ratio may be designated as "narrow," 
"wide," or "medium." These terms do not represent 
exact limits, to which there is universal agreement. 
A narrow ratio is one where the proportion of protein 
is relatively large, not less perhaps than 1:5.5. A 
wide ratio is one where the carbohydrates are very 
greatly predominant, or in larger proportion perhaps 
than 1:8.0. Anything between 1:5.5 and 1:8.0 may 
properly be spoken of as a medium ratio. 

For the purpose of illustration a few feeding stand- 
ards are given in this connection. These are selected 
from standards proposed by Wolff, as modified by 
Lehmann. (See full table in appendix.) They refer in 
all instances to animals weighing 1,000 pounds: 

For 1,000 pounds Jive weight daily 

Total 
Diges- Diges- diges- 

Dry tible tible Diges- tible Nutri- 

sub- pro- carbohy- tible organic tive 

stance tein drates fat matter ratio 
lbs. lbs. lbs. lbs. lbs. 

Cow, yield milk, 22 lbs... 29 2.5 13 .5 16 1:5.7 

Fattening steer, 1st per. . . 30 2.5 15 .5 18 1:6.5 

Horse, medium work 24 2. 11 .6 13.6 1:6.2 

These and other standards will be discussed later 
when we come to consider the feeding of the various 
farm animals. Our present purpose is simply to make 
clear the steps necessary to bringing the quantity and 



Calculation of Standard Rations 285 

composition of the ration into conformity with the 
standard selected. 

As a means of showing the steps involved in cal- 
culating what a ration is, and how to improve it if 
necessary, we will assume that it is desired to learn 
whether a food mixture which a milch cow is eating 
is what it should be, and if it is not, how to make 
it so. The standard ration for a 1,000-pound cow, 
giving twenty -two pounds of average milk, expressed 
in terms of water -free nutrients, has been given in 
the preceding table. 

The first point which requires our attention is that 
this standard is mainly expressed in terms of water - 
free digestible nutrients. This means that we must 
take into account the composition and digestibility of 
the particular feeding stuffs which enter into a ration 
if we would discover what it really is supplying of 
available food compounds. It is evident that usually 
feeders cannot have their cattle foods analyzed, and 
so they must resort to the tables of averages of com- 
position and digestibility, which are, or may be, in the 
hands of every farmer. But what figures shall be 
selected for use ? As we have learned, feeding stuffs, 
especially fodders, differ within quite wide limits in 
what they contain and in what the animal will dissolve 
from them, according to the stage of growth and con- 
ditions of curing, etc., and an average percentage of 
protein or an average coefficient of digestibility is 
likely to differ widely from the actual facts as per- 
taining to a particular material. All that can be 
done is to select as nearly as possible the figures which 



286 The Feeding of Animals 

have been found for feeding stuffs in the condition of 
those which are to be fed. If the hay is from mature 
grass use the composition percentages and digestion 
coefficients given for such hay; if the silage is from 
mature corn, pursue a similar course in this case, and 
so on. Difficulty will be met in always finding suit- 
able figures, because without question there has been 
a failure to properly classify tables of composition and 
digestibility on the basis of the character of the ma- 
terials. 

The assumed ration which we wish to find out 
about consists of 

lbs. lbs. 

Late cut timothy hay. . 10 Hominy chops 2 

Corn silage 25 Winter wheat bran .. . 3 

The averages for composition and digestibility, 
which are as likely as any to represent these and other 
materials, are the following: 



-Composition « <— Digestibility— < 



a a) 2 a ® 2 

© © ti o h <s u o S 

Timothy hay, late cut 14.1 3.9 5. 31.1 43.7 2.2 45. 47. 60. 52. 

Clover hay, average quality 15.3 6.2 12.3 24.8 38.1 3.3 58. 54. 64. 55. 

Corn silage, mature 79.1 1.4 1.7 6. 11. .8 56. 70. 76. 82. 

Hominy chops 11.1 2.5 9.8 3.8 64.5 8.3 68. 95. 92. 

Wheat bran 11.9 5.8 10.4 9. 53.9 4. 78. 29. 69. 68. 

Linseed meal, N. P 10.1 5.8 33.2 9.5 38.4 3. 85. 80. 86. 97. 

The first step in the calculation is to find out what 
percentages of digestible material the components of 
our proposed ration contain, and we shall obtain these 



Calculation of Standard Rations 287 

by multiplying the percentages of composition by the 
coefficients of digestibility and dividing the product by 
100; that is, if timothy hay contains five per cent of 
protein, 45 per cent of which is digestible, then forty- 
five hundredths of five will be the percentage of diges- 
tible protein in the hay. In this way the following 
figures were obtained. The percentage of digestible 
carbohydrates represents the sum of the quantities di- 
gested from both the crude fiber and the nitrogen - 
free extract. Tables are now published which show 
percentages of digestible ingredients, and which will 
render this calculation largely unnecessary: 

Total 
Digestible digestible 

Digestible carbohy- Digestible organic 
protein drates fat nutrients 

% % % % 

Timothy hay, late cut 2.3 40.8 1.1 44.1 

Clover hay, average quality 7.1 37.8 1.8 46.7 

Corn silage, average quality. .9 12.6 .6 14.1 

Hominy chops 6.7 61.3 7.6 75.6 

Wheat bran 12. 39.8 2.7 54.5 

Linseed meal 28.2 40.6 2.9 71.7 

The second step is to calculate the pounds of digest- 
ible nutrients in the quantities of the several feeding 
stuffs to be used. It is clear, for instance, that ten 
pounds of hay will contain ten one -hundredths of the 
amounts in one hundred pounds, so we simply need to 
multiply the percentage of digestible protein and so on 
by ten and divide by one hundred in order to learn what 
ten pounds of hay will furnish to the animal. If we make 
this computation for each constituent of each feeding 
stuff, we reach the figures of the following table 



288 The Feeding of Animals 



Timothy hay, 10 lbs. 
Corn silage, 25 lbs.. . 
Hominy chops, 2 lbs. 
Wheat bran, 3 lbs. . . 



)igestibl( 
protein 


Total 
Digestible digestible 
j earbo- Digestible organic 
hydrates fat matter 


Nutritive 
ratio 


lbs. 


lbs. lbs. lbs. 




.23 


4.08 .11 4.42 




.22 


3.15 .15 3.52 




.13 


1.23 .15 1.51 




.36 


1.19 .08 1.63 





.94 9.65 .49 11.08 1:11.5 



Several authors have published tables showing the 
amounts of digestible nutrients in given quantities of 
our feeding stuffs, which still further shorten the work 
that the feeder must do in computing rations. 

When we come \o compare this ration with the 
standard ration we find it is seriously defective in two 
particulars; it contains much too little digestible organic 
matter and the nutritive ratio is too wide. 

In order to correct these faults we must add digesti- 
ble organic matter which contains a much larger pro- 
portion of protein than is found in an}' of the materials 
so far selected, and we must seek such a supply in part 
at least among the highly nitrogenous feeding stuffs like 
the oil meals and gluten meals. It is easy for one with 
experience to see also that all the necessary additional 
organic matter cannot be secured from a highly nitrog- 
enous food without increasing the protein supply un- 
necessarily. In order to avoid this, the amount of 
silage may be raised ten pounds and still not feed an 
excessive quantity. If clover hay is available it would 
also be well to substitute five pounds of it for five 
pounds of the timothy. If, then, we add to the ration 
three pounds of linseed meal we shall approximate more 
nearly to our standard. 



Calculation of Standard Rations 289 

Total 

digestible 
Cartohy- organic Nutritive 

Protein drates Fat matter ratio 

lbs. lbs. lbs. lbs. 

Timothy hay, 5 lbs 11 2.04 .06 2.21 

Clover hay, 5 lfc* 35 1.89 .09 2.33 

Corn silage, 35 lbs 31 4.41 .21 4.93 

Hominy chops, 2 lbs 13 1.23 .15 1.51 

Wheat bran, 3 lbs 36 1.19 .08 1.63 

Linseed meal, N. P., 3 lbs.. .85 1.22 .09 2.16 

2.11 11.98 .68 14.77 1:6.4 

This ration is still below the standard in quantity, 
but as the relation of the nutrients is approximately 
what is called for, it is only necessary to increase the 
quantities of each component about one -fifteenth in 
order to furnish the animal sixteen pounds of digestible 
organic matter. It is, however, a good ration for cows 
of the smaller breeds weighing from 800 to 900 pounds. 

There are several points to be considered in this 
connection. First of all, the standard rations are the 
quantities to be fed per day and per 1,000 pounds live 
weight. This is ordinarily taken to mean that if a 
1,000 -pound cow requires 16 pounds of digestible 
nutrients an 800 -pound cow should be supplied with 
only four -fifths as much, or 12.8 pounds, or that 
a 1,200 -pound horse needs 50 per cent more food 
than one weighing 800 pounds. Unfortunately this 
simple mathematical way of calculating rations does 
not meet the plain requirements of practice. The needs 
of a producing or working animal are not directly pro- 
portional to its size, although it is more nearly so with 
working animals than with those fed for production. 
It is certain that an exact adjustment of a ration to the 

s 



290 The Feeding of Animals 

weight of the animal would produce absurd conditions, 
especially in the case of cows where production and not 
the size of the animal is the main factor. 

However, we cannot ignore the size of the animal 
in determining the quantity of the ration. Concern- 
ing this Armsby says: "The function of the mainte- 
nance ration is essentially to supply heat to the body 
to replace the constant loss that takes place. Now, 
Henneberg has long ago shown that, in round num- 
bers, over 90 per cent of this heat is removed by 
radiation and evaporation. Consequently, we should 
expect the demands of the organism for heat (i. e., 
for maintenance), to be proportional to its surface 
(including lung surface), rather than to its weight, and 
the more recent researches of Rubner have confirmed this 
theoretical conclusion." For the purposes of calcula- 
tion it is assumed that animals are geometrically 
similar figures and therefore that their surfaces are 
proportional to the square root of the cube of their 
weights. Several steers having weights from 1,000 
pounds up to 1,700 pounds would need on this basis 
amounts of digestible food for maintenance propor- 
tional to figures given in the table below : 



Weight of the animal 
approximately 


Proportion of food per 
1 1,000 lbs. live weight 


1,000 lbs. 


100 


1,100 " 


96 


1,200 " 


93 


1,300 " 


90 


1,400 " 


88 


1,500 " 


86 


1,600 " 


84 


1,700 " 


82 



The Nutritive Ratio 291 

For adjusting a maintenance ration to the weight of 
a steer or horse this method seems to have a plausible 
basis, but it is evidently less applicable to dairy cows 
or rapidly growing or fattening animals, for in these 
cases size is not so largely a controlling factor. 

Again, is there a fixed quantity and proportion of 
protein from which it is unwise to deviate ? If we 
are trying to supply the needs of a cow giving twenty - 
five pounds of milk or of a steer gaining two pounds 
of body substance daily, there is without question a 
minimum quantity of food protein absolutely neces- 
sary in each case, but what these minima are has not 
yet been closely determined. These necessary quanti- 
ties are undoubtedly not exactly the same for all 
individuals, although they are not likely to differ 
widely between single animals of the same class and 
productive capacity. It is safe to assert that the pro- 
tein standards are those which it is practicable to 
feed and which unquestionably meet the demands of 
intensive production, but we are not sure thafe when 
other conditions are right 10 per cent more or 10 per 
cent less than the specified quantities would influence 
efficiency either way; in other words, we have no 
proof in those cases where 2.5 pounds of protein is 
the standard for a milch cow that 2.75 pounds would 
not induce larger production or that 2.25 pounds 
would not meet all requirements when the carbohy- 
drates are present in sufficient quantity. 

All this is equivalent to saying that we cannot fix 
exact nutritive ratios. There is, of course, a min- 
imum food energy which is essential for sustaining a 



292 The Feeding of Animals 

particular animal, and the non- nitrogenous nutrients 
should be present in sufficient quantity to protect the 
protein that it may be applied to its peculiar uses 
rather than be consumed for heat production. It 
is more than probable, though, that the nutritive ratio 
may vary considerably from the German standards 
without causing any appreciable influence upon growth, 
work or milk yield. 

We have good reasons for believing, however, that 
when the supply of food meets the requirements of 
the animal as to quantity, the nutritive ratios 
given in the feeding standards provide fully for the 
needs of animals under all conditions. The signifi- 
cant fact is that in practice it is possible to depart 
so widely from these ratios as to greatly diminish the 
efficiency of the ration for specific purposes, and this 
is the justification of standards which may only ap- 
proximate to the best, but which serve admirably as 
a guide in avoiding serious errors. The foregoing 
statements do not mean that the feeding formulas so 
far published are the result of guess-work and rest 
upon no basis of exact observations, for this is not true. 
It is simply intended to point out the fact that we can- 
not now set exact limits to the formulas of nutrition. 

4. The rations should be compounded with refer- 
ence to the quality of the product. Our knowledge 
of the influence of foods upon the quality of meat 
products is indefinite, but that food has an influence 
upon the flavor of milk and upon the chemical and 
physical properties of butter, seems to be fairly well 
established. 



Business Considerations in Selecting Rations 293 

5. Rations should be compounded with reference to 
the home supply of feeding- stuffs and to market prices. 
Economy often demands that the materials in hand 
shall be used even if the ration is not ideal. Again, 
there are several protein foods which may be used, 
and it is often only a question of price in determin- 
ing which should be purchased. Notwithstanding the 
claims of manufacturers, there is no one feeding stuff 
essential to the health of animals or to the highest 
quality of the product, so that the feeder may often 
consider the matter of cost and select the cheapest 
source of protein without in any way impairing the 
ration. 

Those who have carefully followed the preceding 
statements must have become convinced that the selec- 
tion of a ration which shall be the best possible from 
a business standpoint is not a simple matter. We 
must always distinguish between the combination that 
is most efficient physiologically or productively and 
the one that is the source of largest profit. It is often 
the case — perhaps generally — that a food mixture 
which induces a high rate of production is the most 
profitable one to use, but this occurs only when 
business conditions make it possible. Many seem to 
think that if a ration is "balanced" it necessarily meets 
all the requirements for the maximum profit, but this 
is an erroneous view. 

For instance, a farmer somewhat remote from the 
markets may have on hand an abundant supply of 
hay and home -raised grains of such a character that 
it is impossible to compound them so as to conform 



294 The Feeding of Animals 

to the accepted feeding standard for milch cows. If 
the prices of dairy products are low, and those of pro- 
tein feeding stuffs are high, it is entirely possible for 
the farmer to secure more profit from his cows with 
an "unbalanced" ration than with one which has the 
standard nutritive ratio. 

The western stockman can generally afford to waste 
corn on fattening steers rather than use it with greater 
physiological economy by mixing it with purchased 
grains. The cost of the latter would soon offset the 
profits otherwise possible. All this is equivalent to 
saying that practical considerations often justify a 
wide departure from the standard rations. Hill states 
the case well when he says : 

"The study of the requirements of the individual 
animal and the adapting of food to its needs is to be 
preferred to placing the herd, as a whole, upon any 
inflexible ration. The capacity of an animal to re- 
ceive, its ability to produce, the effects of the sundry 
feeds upon the health and condition of the animal, 
upon its appetite and taste, upon the quality of the 
product, the money values of feed and the profits to 
be derived from their use, are important considera- 
tions which do not enter into the make-up of the 
physiological standard, but which are vital factors in 
the feeder's problem. Clearly the physiological stand- 
ards may supplement, and in some measure guide, 
judgment, but cannot take its place." 



CHAPTER XX 

MAINTENANCE RATIONS 

A maintenance ration is one supplying the needs 
of an animal without production of any kind and with 
no loss of body substance. To be more specific, when 
an ox doing no work excretes just the quantities of 
nitrogen and carbon that are contained in the food con- 
sumed, he is said to be eating a maintenance ration. 
The work done by the animal at rest is largely needed 
in the following directions: the chewing of food and 
its movement along the intestinal tract; the muscular 
action of the heart in causing blood circulation; and the 
metabolic activity of the cells in causing the chemical 
transformation of the nutrients. Some work is also 
done in moving the body. The demands upon the food 
for maintenance purposes are therefore entirely for the 
production of muscular energy and heat. 

Nine -tenths or more of a maiutenance ration may 
consist of carbohydrates which, because the income and 
outgo are balanced, are used solely as fuel. Only a very 
small amount of protein is necessarily destroyed by a 
resting animal, although a minimum food supply is 
absolutely essential if the nitrogenous tissues of the 
body are to be kept from wasting. If an animal is 
not eating protein, urea will continue to appear in 

(295) 



296 The Feeding of Animals 

the urine and in time protein starvation will cause 
death. 

Any ration fed for production may be looked upon 
as made up of two parts, that which is needed to main- 
tain the animal and that which may be applied to 
growth or the formation of milk solids. It is possible, 
of course, for the production of milk or wool to occur 
when the cow or sheep is fed what is really only a 
maintenance ration, but the materials for production 
under these circumstances are furnished at the expense 
of the body substance. With what is regarded as liberal 
feeding, from one -third to one -half of a production 
ration is needed for maintenance purposes. It seems 
fitting, then, to speak of a maintenance ration as a fun- 
damental quantity, a knowledge of which is important 
to both science and practice. It is clear that no rational 
understanding of the uses of food can be had unless we 
know what amount is required simply for maintenance, 
and the feeder is certainly helped to a more intelligent 
compounding of rations if he has some means of judg- 
ing how large an excess he is supplying for production 
purposes. Occasionally, too, it is desired to provide 
horses and other animals when not at work with just 
enough food to keep them in a uniform condition with- 
out gain or loss. 

No ration is more easily provided from the ordinary 
farm supply than is that for maintenance, for two 
reasons: (1) because the quantity of available nutrients 
which must be eaten is so small that this ration may 
be wholly or mostly made up of bulky materials such 
as corn fodder and hay; (2) because investigation has 



Maintainance Requirements of Bovines 297 

demonstrated that mere maintenance demands a com- 
paratively small amount of protein and so this ration 
may have a wide nutritive ratio such as pertains to the 
nutrients of the more common farm products. 

MAINTENANCE FOOD FOR BOVINES 

Experiments having for their object a determination 
of the daily quantity of nutrients necessary to simply 
maintain animals of this class were conducted by Hen- 
neberg and Stohman with oxen as long ago as 1858. A 
number of rations were fed and the conclusions which 
were reached were based upon the amount of food 
digested, the gain or loss of nitrogenous tissue by the 
animals and their weights and general appearance. The 
average daily quantities of digestible nutrients which 
appeared to be sufficient to maintain a 1,000 -pound ox 
without growth or loss was approximately 8.2 pounds, 
of which .53 pound was protein, the whole having an 
energy or heat value of not far from 15,000 Calories. 
Because of the high temperature of the stalls used in 
the above-named experiments, Wolff estimated later 
that for winter feeding the standard should be 8.9 
pounds of digestible nutrients, of which .7 pound 
should be protein, the energy value being approximately 
16,000 Calories, and even until now Wolff's figures are 
published as the standard maintenance ration. 

It is certainly time that this standard should be 
revised. The earlier experiments on which it was 
based furnished data insufficient for accurate con- 
clusions, for the only means of judging whether the 



298 • The Feeding of Animals 

animals were gaining or losing body substance were 
the changes in live weight, which cannot be regarded 
as conclusive evidence. Some of the earlier feeding 
experiments conducted in the United States, especially 
those of Sanborn and Caldwell, indicated that a ra- 
tion based on Wolff's standard was capable of caus- 
ing a material growth of steers, and the accuracy of 
Wolff's figures was called into question. Later obser- 
vations of a more exact character have shown quite 
conclusively that a 1,000 -pound steer may be main- 
tained without loss of body substances on considerably 
less than 8.9 pounds, or even 8 pounds, of digestible 
nutrients per day. 

Elaborate experiments by Kuhn from the years 
1882 to 1890, afterwards discussed by Kellner, were 
regarded by the latter as justifying the conclusion 
that the minimum quantity of digestible organic mat- 
ter which will maintain a 1,000 -pound mature ox at 
rest is 7.3 pounds, .7 of a pound of which should be 
protein. Later Armsby, in presenting the results of 
experiments of his own in connection with a critical 
review of Kiihn's work, concludes that "we may place 
the average maintenance of a steer weighing 500 kgs. 
(1,100 pounds) and receiving only a mainly coarse 
fodder at 13,000 Calories of available energy." As 
Armsby found one gram of digestible . matter from 
timothy hay to be equal to 3.62 Calories of available 
energy, 13,000 Calories would equal 7.92 pounds of 
digestible matter from this source. This would be 
the same as 7.4 pounds for a 1,000-pound animal. 
(See method of calculation in Chapter XIX.) 



Maintenance Rations 299 

Still later, Kellner, basing his figures upon extensive 
researches by himself and associates, which are the most 
elaborate so far made, gives us the following as the 
minimum quantities which will satisfy the maintenance 
needs of mature animals of different weights: 



Approximate weight 
of animal 


Energy 
Cal. 


Digestible 

organic substance from 

average meadow hay 


lbs. 




lbs. 


1,000 


10,740 


6.75 


1,100 


11,520 


7.22 


1,200 


12,280 


7.72 


1,300 


13,010 


8.18 


1,400 


13,720 


8.62 


1,500 


14,420 


9.06 



The necessary quantity of available nutrients may 
be larger if only very ripe, coarse food is fed, than if 
the ration is part grain, because of the somewhat less 
available energy from the digested part of the former. 
In order to express a maintenance ration for bovines 
in terms of hay and grain, there are given in this con- 
nection several mixtures, which, on the basis of aver- 
age composition and digestibility, will furnish quite 
closely the necessary digestible matter, using Armsby's 
conclusions as the basis for calculation : 

To maintain a 1,000-pound animal 

{ 12 lbs. average timothy hay. f 23 lbs. mature corn silage. 

1 3 lbs. wheat bran. 3 i 5 lbs. timothy hay. 

I 3 lbs. wheat bran. 

[8 lbs. corn stover. ( 5 lbs. timothy hay. 

2^6 lbs. clover hay. 4^5 lbs. clover hay. 

( 3 lbs. corn and cob meal. ( 4 lbs. corn and cob meal. 

5. 15% lbs. good mixed hay. 



300 The Feeding of Animals 

These combinations are merely illustrative. Many others 
furnishing an equivalent quantity of available nutri- 
ents may be used. Doubtless these various mixtures 
will not show equal efficiency. Ration No. 3 would 
probably be more satisfactory than No. 5, because of 
greater palatableness. All such facts as the proportion 
of grain in the mixture, the stage of growth of the 
fodder, whether early or late cut, immature or mature, 
the amount of moisture present, as in stover, and the 
completeness of preservation, will have an influence 
upon the nutritive effect of a ration, and these factors 
must be considered according to the best judgment of 
the feeder. It is possible, without question, to main- 
tain an animal on one fodder alone, such as hay, but 
for several obvious reasons it is better to feed a mix- 
ture . 

The maintenance rations heretofore stated apply to 
a 1,000 -pound animal. For animals weighing more 
or less the quantity should be increased or diminished, 
but not in just the ratio in which the animal varies in 
weight. For information on this point the reader 
should refer to what is given in the chapter on com- 
pounding rations. 

MAINTENANCE FOOD FOR HORSES 

The general facts which have been presented in re- 
lation to the function and character of a maintenance 
ration are as applicable to horses as to bovines. It 
is true, however, that rations simply sufficient for 
maintenance purposes have a very limited application 



Maintenance Requirements of Horses 301 

with horses, because in nearly all cases they are at 
least used for occasional driving or light work, and 
even if merely "boarded," regular exercise is necessary 
to their welfare. 

If recent conclusions are sound, a horse needs 
somewhat less digestible food for mere maintenance 
than a steer of equal weight. Zuntz, who has so 
thoroughly studied the nutrition of the horse, con- 
cludes, after a critical survey of the results of other- 
men in connection with the elaborate data from his 
own extended investigations, that a 1,000- pound horse 
can be maintained on 6.4 pounds of nutrients, pro- 
vided the total ration contains not more than three 
pounds of crude fiber. This means that the nutrients 
should come from a mixture of hay and grain if this 
minimum quantity is to be sufficient. Were only hay 
to be fed the necessary nutrients would probably ex- 
ceed the amount named. 

(irandeau in his experiments found that three horses, 
whose mean weight was 852 pounds, were maintained 
for fourteen months on 17.6 pounds of hay per day, 
from which the three animals digested an average of 
6.06 pounds of organic matter. Using the method of 
computation already described, this is equal to 6.75 
pounds of digestible nutrients for a 1,000 -pound 
horse, a result not greatly different from that of 
Zuntz. 

The latest conclusion of Wolff was that a 1,100- 
pound horse should have for maintenance at rest 7.26 
pounds of digestible organic matter daily, exclusive of 
the digested crude fiber, which would be the same as 



302 The Feeding of Animals 

6.78 pounds of fiber-free nutrients for a 1,000 -pound 
horse. As Wolff regarded the fiber as useless to a 
horse, either for maintenance or for production of 
work, the last figures represent his estimate of the 
maintenance needs of a horse at rest. 

It is proper to remark that Wolff's views as to the 
nutritive value of crude fiber are not generally accepted. 

In calculating rations for horses, the coefficient of 
digestibility obtained in experiments with this class of 
animals should be used, coarse fodders, as stated 
previously, not being so efficiently digested by horses 
as by bovines or sheep. For this reason, the gross 
weight of the maintenance food for horses may be as 
great as that for ruminants, though the actual nu- 
trients needed are less. Accepting 6.6 pounds of 
digestible organic matter as the daily requirements of a 
resting horse, the following rations would maintain a 
1,000- pound animal for one day: 



( 16^ lbs. medium quality 
( mixed hay. 



5< 



12 lbs. mixed hay. 
3% lbs. bran, or 
3 lbs. oats, or 
, 2X Ihs. cracked corn. 



f 10 lbs. timothy hay. 

"1 5 lbs. oats. 

[ 10 lbs. timothy. 

, 1A ni ,, , 6 i 10 lbs. carrots. 

_ ( 10 lbs. timothy hay. 

3 j a iv, ^ a ^2}£ lbs. corn. 

( 4 lbs. cracked corn. /i 

{10 lbs. mixed hay. 
10 lbs. carrots. 
2% lbs. oats, 

{10 lbs. mixed hay. 
8 lbs. carrots. 
3% lbs. bran. 



Maintenance Rations 303 

These rations serve as examples and also indicate 
how with ten pounds or twelve pounds of hay the sev- 
eral grains mentioned may be combined to give a main- 
tenance ration. It is not wise to feed a horse on hay 
alone, even when doing no work. Ten to twelve pounds 
of hay are enough coarse fodder, which may be supple- 
mented to advantage by both roots and grain. 



CHAPTER XXI 

MILK PRODUCTION 

Milk, like all other animal products, is derived from 
the food. Its secretion stands almost unrivaled as an 
example of the rapid, extensive and continuous trans- 
formation of the food into animal compounds. In no 
other instance, except perhaps in the case of the earliest 
growth of animals, is so large a proportion of the 
digested nutrients utilized in building new material or 
is there so intimate a relation between the extent and 
kind of the feeding and the extent and character of the 
resulting product. For these and other reasons, the 
successful feeding of milch cows requires, perhaps, 
greater expertness and a wider knowledge of facts than 
any other department of animal husbandry. This will 
appear more fully as we continue to develop this subject. 

It is not proposed in this connection to enter into 
an elaborate discussion of the chemistry and secretion 
of milk, for this is presented elsewhere in the series 
of which this volume is a part. It is essential to 
present purposes, however, that we call to mind certain 
facts which are pertinent to a consideration of the food 
relations of milk formation. 

Milk is a fluid that is secreted by all mammals in a 
gland which with the cow is called the udder. It con- 

(304) 



Composition of Milk 305 

tains water and solids, the latter being made np of 
mineral compounds, proteids, fats and sugar. The 
average composition of normal cow's milk, excluding 
samples of unusual character, according to a compila- 
tion by Van Slyke of 5,552 American analyses is as 
follows : 

Total solids Ash Proteids Fats Sugar Water 

% % % % % % 

12.9 .7 3.2 3.9 5.1 87.1 

The variations in the composition of cows' milk are 
large, the proportion of water ranging under per- 
fectly normal conditions from 84 to 89 per cent, with 
occasional analyses entirely outside these limits. 
The chief known causes of such variations are breed, 
individuality, period of lactation, and nervous dis- 
turbances. There are material daily fluctuations as 
well, for which no reasons can now be assigned. 
These changes are mostly in the proportions of water 
and total solids, for the composition of the solids, that 
is, the relative proportion of proteids, butter fats and 
sugar, is remarkably constant in, the same animal. The 
effect of breed in cows is illustrated by averages ob- 
tained in breed tests at three experiment stations: 

Hoi stein Ayrshire Jersey 

% % % 

Total solids 12.2 12.9 15. 

Fat 3.4 3.6 5.3 

Solids not fat 8.8 9.3 9.7 

These variations and those due to other causes are 
important in considering the relation of milk forma- 

T 



306 The Feeding of Animals 

tion to nutrition, because the food expense of milk is 
determined, other things being equal, not by the vol- 
ume but by the milk solids elaborated, for which 
reason the draft upon the supply of nutrients, water 
excepted, is greater for the secretion of 100 quarts 
of Jersey milk than for the same quantity of Holstein 
milk. In studying the economy of milk production, 
therefore, we should consider the relation of food to 
milk solids and not to milk volume. 

MILK SECRETION 

There is no milk in an animal's food, that is to 
say, hay and grain contain no casein, butter fat or 
milk sugar. They do contain nutrients, which, when 
subjected to the vital processes of the animal, are 
ultimately transformed into the constituents of milk. 
The mammary gland is not a sieve through which cer- 
tain compounds in the blood are strained into the udder 
cavities, but it is a specialized tissue in which wonder- 
ful and extensive chemical changes occur. Here, for 
the first time, we find casein, the mixture of compounds 
known as butter fat, and a sugar unlike any that is 
found in plants, or in aii} r other part of the animal 
organism. Vegetable fats contain glycerides similar to 
some of those found in milk, to be sure, but not in 
the same number or proportions. One fact, moreover, 
which dairymen have been slow to recognize in all its 
significance, is that the udder of each individual cow 
is a law unto itself in the characteristics of the milk 
which it secretes, and is not subject in any large de- 



Origin of Milk Solids 307 

gree to control through feeding or other treatment 
that is not actual abuse. 

The manner of milk secretion is something of which 
we know but little, and this is, perhaps, not immedi- 
ately important to the dairyman. The food source of 
the constituents of milk is, on the other hand, a mat- 
ter of great practical interest, and here we have infor- 
mation more or less definite. 

Sources of milk solids. — The previous discussion of 
the functions of nutrients must have made it clear that 
the proteids of the milk can have only one source; 
viz., the proteids of the food, a unanimous conclusion 
which rests upon experimental evidence as well as 
upon the universally accepted truth that the animal 
organism does not have the power to construct pro- 
teids from simpler compounds. It now seems quite 
certain that the proteids are the only constituents of 
milk which must have their origin exclusively in the 
food proteids, for we have apparently sound reasons 
for believing that milk sugar and butter fat are con- 
structed, in part at least, from carbohydrates. In an 
investigation at the New York Agricultural Experiment 
Station as to the food sources of milk fat, two cows, 
both of which gained materially in live weight during 
experiments continuing two months or over, produced 
respectively nineteen pounds and forty pounds more of 
butter -fat than could be accounted for from the food 
fat and available proteids. The amount of digestible 
food fat supplied was relatively insignificant and the 
secretion of milk fat seemed to be related in no direct 
way to the protein exchange. These observations led 



308 The Feeding of Animals 

straight to the conclusion that carbohydrates are milk 
fat formers. The extent to which food fat assists 
in the production of milk fat is not yet determined. 
It cannot be safely asserted that the ingested fats do 
not pass directly into the milk, but it seems quite 
evident that the larger part of the glycerides of milk 
have their origin in the animal. We are not sure, 
either, whether protein is ever a source of milk fat, 
but that it is a necessary source now seems quite im- 
probable. 

The rate of formation of milk solids. — A cow yield- 
ing 6,000 pounds of average milk per year is not re- 
garded as an unusual animal. This means, however, 
the annual production of not less than 780 pounds of 
milk -solids, an amount at least double the dry matter 
in the body of a cow weighing 900 pounds. When 
we consider that this manufacture of new material is 
carried on not only during a single year, but through 
the entire adult life of the animal, we begin to realize 
how extensive are the demands upon the food supply. 
Still more striking is the case of high grade cows 
yielding annually over half a ton of milk solids, and 
when we remember the performance of Clothilde, whose 
26,000 pounds of milk produced in one year certainly 
contained more than 2,500 pounds of solid matter, we 
must regard the cow as possessing wonderful powers 
of transmutation. Her capacity for the rapid and eco- 
nomical production of human food of the highest quality 
is not equaled by an other animal. 

No facts could more forcibly illustrate the necessity 
of liberal and proper rations for the milch cow. 



Food Requirements for Milk Production 309 

THE AMOUNT AND CHARACTER OF THE RATION FOR 
MILK PRODUCTION 

This ration is used in various directions. It must 
supply the raw materials for milk formation, provide 
for the growth of the foetus, sustain the effort of 
milk secretion and maintain the usual and necessary- 
functions of the animal body. The nature and extent 
of these uses are in part quite definitely understood. 
First of all, the kind and quantity of milk solids may 
be estimated for any given case. The daily production 
of thirty pounds of average milk, a performance rea- 
sonably to be expected in a good herd, involves the 
elaboration of 3.87 pounds of milk solids. For mere 
maintenance it is fair to assume that the food require- 
ments of the cow and steer would not be greatly un- 
like, disregarding the demand for energy utilized in 
milk secretion, and for the material used in the growth 
of the young. On this basis the milk solids and the 
mere maintenance of the cow call for about 11.25 
pounds of dry matter daily, a quantity utterly insuffi- 
cient, as experience teaches, to maintain a cow giving 
thirty pounds of average milk. We are led to the 
reasonable conclusion that outside the building of milk 
solids, a large expenditure of food energy is required 
to sustain the nerve force, metabolic cell activity and 
warming of the extra water and food, which are neces- 
sarily involved in milk secretion. This view is sus- 
tained by the results of investigation. In unpublished 
experiments by the writer with two cows in full flow 
of milk, which made only a slight gain in body weight, 



310 The Feeding of Animals 

the available energy of the rations and of the milk was 
determined. The figures reached were approximately 
as follows : 

Cow 10 Cow 12 

wt. 775 lbs. wt. 1,200 lbs. 

Cal. Cal. 

Available energy of ration 27,120 31,300 

Energy of milk solids 8,450 10,200 

Energy not used in milk 18,670 21,100 

Maintenance needs of resting animal. . . 10,100 13,700 

Balance of energy not accounted for . . . 8,570 7,400 

This energy not accounted for, amounting with the 
two cows to more than one -fourth the total available 
energy of the rations, may properly be charged to the 
work of milk formation. Science and practice agree 
in naming 15.5 to 16.5 pounds of digestible organic 
matter as approximately the proper daily amount of 
digestible nutrients for economical milk production 
with a good cow of average size, much less than which 
is not to be considered as generous feeding. The nec- 
essary supply of nutrients will vary somewhat accord- 
ing to the size of the cow, but the gradation of 
quantity should by no means be directly proportional 
to live weight. Productivity independent of size is a 
controlling factor. In general small cows eat propor- 
tionately more food than larger ones. 

The question now arises, What proportion of this 
quantity should be protein ? The actual amount of 
proteids in our thirty pounds of average milk is about 
one pound. If .60 pound is needed daily for mere 
maintenance as in the case of the steer, we can see 
where 1.6 pounds of protein must be used, a quantity 



Food Requirements for Milk Production 311 

which is now regarded as too small when both food 
economy and the efficienc}- of the ration are considered. 
With this amount of protein in sixteen pounds of total 
digestible matter, the nutritive ratio of the ration would 
be about 1:9.5. A ration with as wide a ratio as this 
is regarded by the great majority of careful experi- 
menters, and most intelligent dairymen, as less efficient 
than one richer in protein. While it is not possible 
to point out just how more protein is used, there is no 
question but that a larger quantity promotes the flow 
of milk. Few instances are on record where, in care- 
fully conducted experiment station work, other condi- 
tions being the same, a moderate ration with a nutritive 
ratio of 1:5.5 to 1:6.5 has not proved to be more 
efficient than one equivalent in quantity but with a 
ratio materially wider. The observations of Atwater 
and Woods among the dairy herds of Connecticut, 
where the owners were induced to narrow the rations 
they were found to be using, gave emphatic testimony 
as to the desirability of a larger proportion of protein 
than is ordinarily supplied in a home-grown ration. 
This added protein may not be needed for construction 
uses, but its presence certainly in some way induces 
an increased milk secretion. The chemical changes 
involved in milk formation are obscure and complex, 
and it may be that this extra protein somehow enters 
into these transformations. One view which appears 
to be rational is that the presence of a generous amount 
of circulatory protein stimulates the cells of the body 
to great metabolic activity, thus promoting the secretion 
of milk solids. 



312 The Feeding of Animals 

According to the majority of testimony available, a 
cow of average size and good capacity should receive 
at least 2.25 pounds of protein daily during the full 
flow of milk, the ration to have a nutritive ratio not 
wider than 1:G.5. The nutritive ratio of young pasture 
grass, perhaps as efficient a milk -producing food as we 
have, is even narrower than this, a fact which doubt- 
less explains in part the large flow of milk from 
abundant June pasturage, and which offers a sugges- 
tion for the compounding of winter rations. 

While the importance of nitrogenous feeding stuffs 
to a dairy herd is conceded, there is a tendency with 
certain writers to distort the relation of protein to 
milk production. Their utterances give the impres- 
sion that in feeding milch cows protein is about the 
only factor to be considered. This view is typified by 
the assertion that "a cow gives milk only in propor- 
tion to the protein that she receives," a remark which 
might be made with equal accuracy about carbohy- 
drates. It is true that even if carbohydrates are sup- 
plied in abundance, a depression of the protein below 
a certain limit will diminish the milk flow. It is also 
true that when sufficient protein is fed, a reduction of 
the carbohydrates below the necessary quantity will 
cut down the milk yield. An adequate supply of easily 
digestible carbohydrates is no less important physio- 
logically than keeping up the necessary proportion of 
protein, though the former may be accomplished more 
easily than the latter because of the usual character 
of home -raised crops. 

The following are illustrative examples of well-corn- 



Good Milk Rations 



313 



pounded rations for cows of moderate size and fairly 
large productive capacity : 



10 lbs. clover hay. 
35 lbs. corn silage. 
2 lbs. hominy chops. 
4/^" lbs. wheat bran. 
. 2% lbs. linseed meal, N. P. 



10 lbs. mixed meadow hay. 
40 lbs. corn silage. 

4 lbs. wheat middlings. 

3 lbs. malt sprouts. 

1 lb. gluten meal. 



3^ 



6 lbs. clover hay. 
10 lbs. mixed meadow hay. 
25 lbs. mangels. 

3 lbs. corn meal. 

2 lbs. wheat bran. 

2 lbs. brewer's grain. 

2 lbs. gluten meal. 

12 lbs. clover or alfalfa hay. 
30 lbs. corn silage. 

4 lbs. ground oats. 

3 lbs. ground peas. 

2 lbs. brewer's grains. 



10 lbs. corn stover. 

5 lbs. alfalfa hay. 
25 lbs. sugar beets. 

3 lbs. corn and cob meal. 

3 lbs. buckw't middlings. 
1% lbs. cottonseed meal. 



These rations may be criticised on the ground that 
they are too small to sustain heavy milk production. 
This would be a just criticism for cows of large ca- 
pacity that are furnishing high-priced milk. 

It is the writer's opinion that under ordinary con- 
ditions few cows under 1,000 pounds in weight will 
render larger profit from heavier rations. 

The sources of 'protein for milk production. — The 
dairyman has constantly to face the fact that from the 
usual list of home-grown feeding stuffs it is difficult 
to make up a ration throughout an entire season with 
a nutritive ratio much narrower than 1:8, and a propor- 
tion of protein even as high as this requires a gener- 



314 The Feeding of Animals 

ous admixture of clover in the hay, and the use of 
more or less oats or peas in the grain ration. It 
should not be forgotten that the plants used for for- 
age crops are generally not harvested until they are 
approaching maturity, and as the later growth of 
most plants is largely due to the formation of non- 
nitrogenous compounds, the hay and other fodders 
stored for winter feeding are comparatively poor in 
nitrogen compounds. On those farms where the hay 
crop conies largely from the true grasses, like timothy 
and red- top, and where the corn crop is a prominent 
feature, a home-raised milk ration having a maximum 
efficiency per-unit* of dry matter consumed is not pos- 
sible. On the other hand, where alfalfa and clovers 
constitute a good proportion of the hay, and where 
generous areas of peas and oats are grown, a ration 
compounded from home resources may have a high 
milk -producing efficienc}-. 

It must be confessed, however, that most dairy farms 
are lacking in a proper home-raised supply of the more 
nitrogenous feeding stuffs, and as nearly all dairymen 
depend to some extent upon purchased grain, it is a 
quite prevalent custom for them to seek those by-prod- 
ucts that will strengthen the protein side of the 
ration, a course which they have been led to adopt 
through the teachings of science. It is unquestionably 
true that farmers should be more independent of the 
markets, and they certainly may be if an intensive 
system of cultivating well -selected crops is adopted ; 
but so long as more or less grain will certain ly be 
purchased, it is wise to consider the matter of select- 



Sources of Purchased Protein 315 

ing commercial protein feeds for dairy cows. Those 
from which it is possible to choose are the oil meals, 
the gluten meals and feeds, brewers' grains, malt 
sprouts, peas and buckwheat middlings. The offals 
from the milling of wheat, while somewhat more nitrog- 
enous than the cereal grains, cannot be considered as 
an abundant source of protein, although they are ex- 
cellent components of a milk ration. 

Notwithstanding the claims which trade interests 
may make to the contrary, no one of the above-men- 
tioned feeding stuffs is alone essential to the economi- 
cal production of the best of milk. There is no single 
food or any one combination of foods that is always 
best for dairy cows. Apart from certain considerations 
which will be discussed later, a selection of the source 
of commercial protein is a matter of availability and 
of relative market cost. For instance, when gluten 
meal costs $20 per ton few buyers can afford to pay 
$27 for linseed meal to feed in any considerable quan- 
tity. If prices were reversed, oil meal should be se- 
lected. Both oil meals and gluten products may be 
ignored if ground peas, buckwheat middlings or the 
brewers' residues are available at more favorable prices. 
It is simply necessary that the grain ration shall con- 
tain protein in sufficient quantity and proportion, and 
shall be made up of a variety of materials, better not 
less than three kinds, all of which should be palatable 
and exert no deleterious influence upon the milk or its 
products. There are few grain products that cannot 
be used successfully in grain mixtures, even though 
they are undesirable when fed alone. 



316 The Feeding of Animals 

THE RELATION OF FOOD TO THE COMPOSITION AND 
QUALITY OF MILK 

There is a widely prevailing opinion among the 
farming public that the character of milk is inti- 
mately related to the kind and quantity of food from 
which it is produced, i. e., that a dairyman who is 
possessed, of sufficient knowledge may, by variations in 
the rations, cause material changes in the composition 
of the milk of his herd. This is equivalent to believ- 
ing that thin milk or rich milk, milk rich in fats and 
poor in casein or the reverse, may be obtained at the 
will of the feeder. Such a view in its extreme form 
is very far from the truth. While below a certain 
limit for each cow the quantity of milk is mostly de- 
termined by the ration, other factors, such as breed, 
individuality and period of lactation are much more 
potent than the food in fixing its composition. 

In discussing this topic, it must be confessed first 
of all that the experiments touching its several phases 
have not furnished information satisfactorily definite 
and conclusive in all respects. The testimonj^ arrived 
at is more or less confusing and contradictory. There 
are several directions in which it has been necessary to 
look for the effect of food upon milk: (1) Effect upon 
composition: (a) in changing the proportion of water 
and total solid matter; (5) in changing the relative 
proportions of proteids, fat and sugar; (c) in changing 
the constituents of the fat. (2) Effect upon flavor. 

1. (a) Effect of food upon the composition of milk. — 
In discussing the effect of food upon the proportion 



Influence of Food on Kind of Milk 317 

of total solids, the question is, Can the richness of 
milk be modified by changes in the ration f For in- 
stance, is the milk from a very generous food supply 
richer than that from a moderate or scanty ration, 
or will a highly nitrogenous ration cause a secretion of 
milk with a higher percentage of solids than a ration 
poor in protein f It would probably be generally con- 
ceded that if variations in milk are caused in these 
ways, they are small as compared to those due to 
breed characteristics or to individuality. Can we bring 
about variations sufficiently large to be important ? 
This question has been much discussed and much in- 
vestigated from the work of Kiihn in 1868 down to 
the present day. Many experiments have been con- 
ducted for long periods and short periods in which 
very moderate rations have been compared with very 
large ones, highly nitrogenous foods with those of a 
low protein content, dry with green or succulent ma- 
terials, and grains of the same class with one another, 
and, in a great majority of cases, the verdict has been 
that "no consistent relation appears to exist between 
the quantity or character of the ration and the com- 
position of the milk." The writer has examined the 
results of nearly all the important experiments of this 
character of which he could find a record, and in but 
few cases could he discover that there was a material 
increase or decrease in the proportion of milk solids 
which bore a logical relation to variations in the ration. 
In some cases, a temporary change appeared in the 
milk immediately after a violent change in the ration, 
but in most instances of this kind, there was very 



318 The Feeding of Animals 

soon a return to the animal's normal product. In a 
small proportion of experiments, the milk appeared to 
sustain a permanent though not extensive modification. 
The weight of testimony bears out the statement that 
the quality of milk cannot be changed at will by the 
farmer, but is largely determined by causes not under 
his control, such as breed and individuality, although 
feeding and treatment, especially the latter, have more 
or less influence upon the character of the milk secreted. 
It is possible, even probable, that continuous feeding 
either very poorly or very highly may bring about in 
time a permanent change in a cow's milk, but to-day 
no one is wise_ enough to point out a way of definitely 
controlling this product through the food. 

{b) In the discussions relative to feeding dairy cows, 
another point has received much attention; viz., the 
effect of foods upon the proportions of the constitu- 
ents which make up the dry matter of milk. A popu- 
lar notion has prevailed that it is possible to "feed 
fat into milk," having its origin in part, perhaps, in 
misconceptions as to the manner of milk formation. 
If the mammary gland served simply to capture the 
unchanged constituents of the food, then it might be 
reasonable to expect the milk to partake of the char- 
acter of the digested nutrients and be "fat" or "lean" 
according to the proportions of proteids and fats sup- 
plied to the animal. When, however, we consider that 
this gland has the function of transforming the raw 
material of the food into a milk which is characteris- 
tic of the breed or of the individual in accordance with 
somewhat fixed constitutional limitations, and that from 



Influence of Food on Kind of Milk 319 

the same food the Jersey cow will make Jersey milk 
and the Holstein cow Holstein milk, that a cow which 
starts in life giving thin milk is never transformed into 
a producer of rich milk, we can easily understand the 
general failure to find a recipe for feeding fat into milk. 
Experimenters who have added large quantities of fat 
or oil to a ration have in all but a very few instances 
failed to permanently or even temporarily increase the 
percentage of fat in the milk solids; and, on the other 
hand, rations rich in protein do not appear to cause a 
larger relative amount of proteids in the milk dry sub- 
stance than rations with a wide nutritive ratio. As a 
matter of fact, after years of investigation and intel- 
ligent observation, we are not able to affirm that the 
proportion of fat to other milk solids is in any way 
related to the feeding of the cow, and if apparent ex- 
ceptions to the general experience have been noticed, no 
one has discovered any general method or law whereby 
the exception may be made the rule. In view of our 
present knowledge, certainly no more absurd view pre- 
vails to-day than the belief that the composition of 
the milk solids is subject to the will of the man who 
feeds the cow. 

(c) It should not be inferred from the previous state- 
ments that none of the compounds of the food enter 
the milk as such, or that the qualities of the milk are 
in no way influenced by the character of the ration. 
Such conclusions would not be consistent with the out- 
come of numerous investigations. While it has be- 
come quite evident that the composition of butter, an'1 
therefore its qualities, such as hardness and melting 



320 The Feeding of Animals 

point, are sometimes materially modified by the cow's 
food, information along this line is in a state of con- 
fusion and inadequacy, and it is not now possible to state 
with any definiteness just what influence the various 
feeding stuffs have upon the chemical and physical 
properties of butter. Experimenters are fairly unani- 
mous, however, in concluding that the liberal feeding 
with cottonseed or cottonseed meal has the effect of 
raising the melting point of butter and of diminishing 
the percentage of the volatile fatty acids. On the other 
hand, when gluten meal rich in oil has been intro- 
duced into the ration in generous proportion, the 
butter has been found to melt at a lower point, and 
appeared softer. Certain chemical reactions indicate 
that this decrease in the melting point has been accom- 
panied in some cases at least by an increase in olein, 
a fat which is a prominent constituent of olive oil, 
and is liquid at ordinary temperatures. One set of 
experiments, where gluten meal with different propor- 
tions of oil was used, appears to warrant the conclusion 
that the softening of the butter from feeding this ma- 
terial is not marked when its percentage of fat is 
small, as is the case with some brands of gluten meal 
at the present time. The conclusion which has been 
reached as a result of some experiments, that gluten 
meal causes softer butter than corn meal, the fats and 
other compounds in the two feeds being similar in 
kind, is wholly irrational unless we conclude that the 
larger quantity of fat fed in the former is the cause 
of its specific influence. In a few cases where various 
oils were fed in liberal quantity the butter is re- 



Influence of Food on Kind of Milk 321 

ported to have varied in ways corresponding to the 
composition of the oils, a result not at all improbable. 

In looking over the record of investigations along 
this line it is found that food rich in sugar and other 
soluble carbohydrates is credited with producing soft 
butter, potatoes are charged with the same effect, and 
even cooked or sour foods are said to have a peculiar 
influence. Some writers go so far as to present lists 
of feeding stuffs in the order in which they increase 
the volatile fatty acids, but such definite representa- 
tions must at present be taken "with a grain of salt." 
In most instances, no relation is established between 
the effect observed and the market value of the butter. 
In fact, it is distinctly asserted by one or two experi- 
menters that there is no clear relation between the 
melting point and hardness. It seems quite probable 
that when the ration includes a variety of grain foods, 
practically the entire list of feeding stuffs may be uti- 
lized under proper conditions without damaging the 
market value of the butter for local consumption. 

2. Effect of food upon the flavors of milk and its 
products. — It is not possible with our present knowl- 
edge to establish a relation between the flavors of dairy 
products and the presence of definite compounds. What- 
ever causes flavor in milk or butter is generally present 
in such minute quantities that even if the nature of the 
substance was known the determination of its amount 
would be bej r ond the skill of the chemist. Milk satis- 
factory to the critical taste and smell may be so simply 
because bad flavors are absent, or there may be present 
the positive influence of some constituent of the ration. 

u 



322 The Feeding of Animals 

It is probably safe to assert that compounds in the food 
may pass into the milk as such, and the superiority of 
June butter, if such exists, may be due to the almost 
imponderable volatile odors which are derived from the 
3^oung grasses. Nothing is more certain than that the 
deleterious odors of certain foods and those that per- 
tain to the stable are often absorbed by milk, as, for 
instance, when cabbage, turnips and onions are fed. 

It is generally believed that odors or flavors from 
the foods which affect milk in so marked a manner 
may enter it in two ways, by transference through the 
animal and by absorption from the air of the stable. 
Unfortunately, however, the various views which are 
accepted regarding this matter are not based upon sat- 
isfactory experimental evidence. Some farmers declare 
in most positive terms that they can feed turnips to 
their cows with no harm to the quality of the butter, 
while others assert that this cannot be done. It is 
claimed that the time of feeding, whether just before 
or just after milking, has a marked influence upon the 
extent to which turnips and similar materials impart a 
flavor to the milk. Concerning all these points, we 
have but little evidence other than the somewhat loose 
observations of practice. 

The results of a few quite recent experiments are 
worthy of mention in this connection. King and Far- 
rington, of the Wisconsin Experiment Station, declare 
that their experiments show beyond question that when 
silage is fed before cows are milked a sweetish flavor 
is imparted to the milk, and that such a flavor is not 
detected when the silage is fed after milking. These 



Influence of Food on Kind of Milk 323 

experimenters also placed milk within a silo exposed 
to the air for an hour, and silo air was forced through 
the contents of some cans. In seven out of twenty 
tests no silage odor could be detected, and it was less 
in any case than when silage was fed before milking. 
Canadian experiments, on the effect of feeding tur- 
nips, seemed to warrant the conclusion that the mere 
presence of a strong turnip flavor in the stable did not 
affect the milk, and that when the turnips were fed in 
small quantity (one peck) daily no flavor was imparted, 
but that when one bushel or more was given the flavor 
appeared whether the turnips were fed before milking 
or after. On the other hand, in a Norwegian experi- 
ment as high as 2.8 bushels of turnips were fed to 
cows daily, and no turnip taste could be detected in 
the milk. The cows were fed in one place and milked 
in another, and so the experimenter concluded that 
when this taste is observed it is due to absorption by 
the milk after it is drawn. That warm milk may ab- 
sorb odors is shown by Russell. These observations 
illustrate fairly the somewhat inclusive condition of 
the testimony on the points in question. 



CHAPTER XXII 

FEEDING GROWING ANIMALS 

A discussion of rations for growing animals re- 
lates in large part to the uses of food for constructive 
purposes. The formation of bone and soft tissue pro- 
ceeds rapidly in the young organism, the nutrition of 
which must be adapted in kind and quantity to large 
demands in this direction. This is true of all young 
domestic animals. The actual daily increase in live 
weight of a well -nourished calf may be as great as 
that of a mature steer when liberally fed. It is not 
unusual for the former to gain two pounds a day in 
weight, and 1.5 pounds is less than would be satis- 
factory. It is possible to calculate approximately what 
this growth would require of actual dry matter. The 
only analysis of a calf's body which is available is 
that made by Lawes and Gilbert, from which it ap- 
pears that the entire animal when fat has approxi- 
mately the following composition : 



Water 


Ash 


Protein 


Fat 


% 


% 


% 


% 


64.6 


4.8 


16.5 


14.1 



A gain of 1.5 to 2 pounds live weight means a storage 
of not less than .24 to .33 of a pound of dry protein in 
the animal's body, and the laying on, when the animal 

(324) 



Use of Food by Growing Animal 325 

is fed for fattening, of .21 to .28 of a pound of actual 
fat. Here, then, is an actual daily increase of dry- 
body substance of .45 to .61 of a pound, which may be 
equal to one -fifth or more of the total dry substance 
of the ration. 

More definite information is furnished by the some- 
what limited studies which have been made of the 
metabolism of the calf. As long ago as 1878 Soxhlet 
studied the income and outgo of three young calves 
fed on whole milk. One pound of milk solids, prac- 
tically all digestible, produced one pound increase of 
live weight, which was equivalent to a storage of at 
least one -third pound of body dry substance, a food 
efficiency for growth practically ten times that exhib- 
ited with animals somewhat mature. Nearly 70 • per 
cent of the protein of the food was fixed in the bodies 
of these calves, and only a small proportion was broken 
down, conditions quite the reverse of those which per- 
tain to the use of food by well -grown steers. Seventy- 
two per cent of the phosphoric acid and 97 per cent 
of the lime were retained for the purposes of growth. 
Later experiments with calves fed on rations in whole 
or in part composed of skim -milk, show a deposit of 
from 26 to 43 per cent of the protein. These results 
illustrate the vigor with which a young animal assimi- 
lates food for growth, and explain the greater profits 
from feeding young animals as compared with feeding 
those more or less mature. 

During recent years there has been much discussion 
and many experiments touching the influence of food 
upon the development of the animal body. Several 



326 The Feeding of Animals 

experimenters, notably Sanborn and Henry, in this 
country, have compared the growth of swine on rations 
presenting extreme differences, as, for instance, mid- 
dlings and blood against corn meal alone, or shorts 
and bran against potatoes, tallow and corn meal. As 
would be expected, the development of the two lots 
of pigs was in these cases greatly unlike. Those fed 
on the nitrogenous rations contained more blood than 
the other ; their organs, such as the kidneys and liver, 
were much larger in proportion to the weight of the 
body, the bones were stronger and the proportion of 
muscle in the carcass was much greater. These differ- 
ences were very marked. It should not be forgotten, 
however, that these were extreme and somewhat un- 
usual rations. It is doubtful whether there are gen- 
erally sufficient differences in the food combinations of 
ordinary practice to occasion such marked differences 
of body structure. 

At the Cornell University Experiment Station lambs 
fed on oil meal and bran made a much more satisfac- 
tory gain than a lot the grain ration of which was 
corn meal' alone, but the photographs of the carcasses 
do not show a larger proportionate growth of muscular 
tissue from the nitrogenous foods. 

An elaborate study of the influence of the ration 
upon the composition of the carcass was made at the 
Maine Experiment Station, where two lots of steers 
were fed from calfhood on rations widely unlike in 
their nutritive ratio. The grain food of one lot was 
oil meal, wheat bran and corn meal, and of the other 
lot corn meal, mixed with a minimum proportion of 



Relation of Food to Character of Growth 327 

wheat bran, the nutritive ratios being respectively 1:5.2 
and 1:9.7. One animal from each lot was killed at the 
end of seventeen months of feeding and the others at 
the end of twenty -seven months, the entire bodies of 
the four steers, exclusive of the skins, being analyzed. 
It was found that the composition of the several ani- 
mals did not differ materially. The amount of growth 
was at first more rapid with the more nitrogenous 
ration, but the kind of growth appeared to have been 
controlled by the somewhat fixed constitutional habits 
of the breed. Nevertheless, the evidence of all well- 
conducted experiments and of all experience is unani- 
mous in emphasizing the necessity of supplying in the 
food of young animals an abundance of those nutrients 
which are needed for the building of bone and muscle. 
A satisfactory development of the organism at maturity 
is insured only when the early growth is liberal and 
uniform, and is such as to produce strong bone and a 
vigorous muscular system. More than this, there is 
induced by proper nourishment a lively temperament 
or energy of body that may be called vital force, which 
chemical analysis cannot search out or measure, but 
which gives the chief value to certain classes of ani- 
mals and is desirable in all. It is believed that this 
condition of strong vitality is promoted by a liberal 
supply of the proteids in the food. 

In considering the feeding of young animals, we 
recognize the mother's milk as in general supplying 
the necessary nutrients in the best forms and propor- 
tions. It is true in the case of cows that the very 
rich milk of the butter breeds when generonslv fed 



328 The Feeding of Animals 

often causes a serious disturbance of the calf's diges- 
tive organs, but the fact remains that casein, milk fat 
and milk sugar are adapted through Nature's design 
to the digestive processes and the nutrition of young 
animals. Moreover, milk is rich in the mineral com- 
pounds needed for bone formation. When, therefore, 
it becomes necessary or desirable to substitute other 
food for the mother's milk, it is essential not to act 
counter to physiological necessities and conditions. 

One fact of importance is that the very young ani- 
mal is somewhat undeveloped in its capacity to digest 
the starchy grains and similar substances, the secre- 
tions necessary for this purpose not yet being abundant. 
It follows, then, that the first substitute for whole 
milk should not consist largely of the insoluble carbohy- 
drates, like porridge from any of the cereals. Again, 
the young animal's stomach is at first unfitted for re- 
ceiving and utilizing bulky, fibrous food. Some time 
must elapse before the calf or colt can be expected 
to obtain much nourishment from grass, hay or like 
materials. 

THE FEEDING OF CALVES 

The most successful way of feeding calves to secure 
rapid growth, especially to produce veal of the highest 
quality, is to supply them with the mother's milk up 
to the limit of their capacity. Where they are to be 
raised for stock purposes, satisfactory growth may be 
maintained with the use of substitutes for whole milk, 
which is fortunate, because with the exception of the 
western plains, where cows are cheaply kept simply 



Food for the Calf 329 

for breeding purposes, or where a breeder is selling 
his increase at fancy prices, the feeding of whole milk 
is not warranted by the value of the resulting animal. 

For this reason, most dairymen, particularly those 
who sell milk as such, kill the calves at the age of a 
few days, excepting perhaps during that portion of the 
year when veal sells at a very high price. On the 
other hand, many dairymen who have a supply of 
skimmed milk, successfully feed this to growing calves, 
when it is desired to raise heifers or even steers. Ex- 
perience has shown that it is entirely practical to do 
this, and it is certainly economical, for experiments 
have demonstrated that as prices average, the cost of 
a pound of growth so produced is about one -third 
what it would be if whole milk were fed. 

As a guide in providing a substitute for whole 
milk, it may be stated that a vigorous calf should 
very early be made to eat daily not less than three 
pounds of highly digestible matter with a nutritive 
ratio at first not wider than that of whole milk solids. 
The exclusive feeding of skimmed milk for any length 
of time is not to be recommended. Experience shows 
that for young calves it should be so combined with 
other materials that a mixture is obtained which, so 
far as possible, resembles whole milk in its nutritive 
ratio. After the fat is removed from the milk, the non- 
nitrogenous compounds are probably not present in 
sufficient proportion to protect the protein from waste 
as fuel. No feeding stuff appears to be a more effi- 
cient amendment of skimmed milk for the earliest 
feeding than flaxseed meal cooked into a porridge. 



330 The Feeding of Animals 

The explanation of this is the high percentage of oil 
in this meal, its low content of starch, and its high 
rate of digestibility. Besides, it appears to promote a 
healthy condition of the organs of digestion. Oil meal 
may be used in its stead, but it is less desirable at 
first. 

The calf should be allowed whole milk for a few 
days, not necessarily more than a week, when it may 
be gradually changed over to skimmed milk and flax- 
seed meal. An admirable mixture is prepared by 
cooking the flaxseed meal in water in the proportion 
of one to six by volume, and adding a small amount of 
this (the equivalent of three or four tablespoonfuls 
of the dry meal at first) to eighteen or twenty pounds 
of warm skimmed milk, which may serve as a day's 
ration. The quantity of meal should be gradually in- 
creased up to one pound a day inside of a few weeks. 
In six or eight weeks the calf should be allowed ac- 
cess to dry oatmeal, or oatmeal and wheat middlings, or 
the oatmeal and middlings may be boiled with the 
flaxseed meal and mixed with the milk. After ninety 
days the flaxseed meal may be dropped for the sake of 
economy. The calf will soon appreciate a wisp of 
early cut hay, some coarse food becoming a necessity 
before many months pass. This method of feeding 
has repeatedly produced rapid growth and fine ani- 
mals. For heifers it is probably to be preferred to 
whole milk feeding, as it is fully as conducive to the 
vigorous development of the muscular system and is 
less likely, perhaps, to promote a tendency to lay on 
body fat. 



Feeding Lambs for Rapid Growth 331 

Hay tea is sometimes used as a milk substitute, 
but it is a poor one. Only a small proportion of the 
nutrients of hay is soluble, and the water extract is 
a dilute and comparatively innutritious food for a grow- 
ing animal, the use of which can be justified only in the 
absence of milk in any form, and which, when used, 
must be very liberally fortified by grain feeds. 

THE FEEDING OF LAMBS 

The first growth of lambs is chiefly from the moth- 
er's milk, and we have little occasion to consider sub- 
stitutes for this food. The fact first in order and most 
important in this connection is that well-fed mothers 
are absolutely essential to rapid growth. A lamb must 
be fed through its dam. Nothing is more pitiable than 
the sight of a pair of hungry twin lambs making an 
effort to satisfy their insistent demands for growth 
with the milk furnished by a small, lean, under -fed 
mother. It is a repetition of the cruel command to 
"make bricks without straw." As a matter of fact, the 
treatment of the ewe before the birth of her young 
should be such as to prepare her for the strain of 
supplying a generous flow of milk. 

Ewes that are suckling lambs, while fed from the 
barn, should be supplied with good clover or alfalfa 
hay, or hay from fine mixed grasses. Pea and bean 
straws are excellent coarse feeds for sheep. Timothy 
hay is an abomination as sheep food, especially under 
these conditions. The grain ration should not be less 
than three -fourths of a pound daily, made up in part 



332 The Feeding of Animals 

of one or more of the highly nitrogenous feeding stuffs. 
It is also desirable to feed a small proportion of some 
succulent food. What is needed is a milk -producing 
ration, and the discussion of feeding cows for milk 
production in a preceding chapter is in part pertinent 
to ewes. Corn, oats, wheat bran or middlings, beans, 
peas, gluten and oil meals are all useful in making up 
such a ration. With safe feeding one pound daily of 
a mixture of oil or gluten meal, one part, wheat bran, 
two parts, and corn meal, two parts, combined with 
two or three pounds of roots or silage and what coarse 
feed the appetite will bear, is a good milk ration, and 
will bring the ewes through the strain of suckling 
lambs in good condition. If it is desired to produce 
the most rapid growth of the lambs, they should also 
have access from nearly the first to a grain mixture. 
Experiments indicate that this mixture is most eco- 
nomical, especially if the lambs are to be fed later for 
the market, when containing a generous proportion of 
corn meal, to which may be added, among other mate- 
rials, ground oats, wheat bran, gluten feed or meal, or 
oil meal, reference being had to the ruling market prices. 
In an experiment at the Maine Experiment Station 
lambs suckled by grain -fed mothers and with access 
to grain themselves made 75 per cent or more gain 
in live weight than those did that received no grain 
and which were suckled by mothers that ate a limited 
grain ration. Five and three -fourths pounds of grain 
produced one pound of growth. At the Wisconsin 
Experiment Station, as an average of three trials, lambs 
fed grain before weaning gained in ten to twelve weeks 



Qualities Demanded in Horses 333 

seven and a half pounds more each than those not so 
fed. Four pounds of grain produced one pound of 
live weight. 

Liberal feeding means more economical growth, a 
higher quality of product and the earliest possible mar- 
ket. The foregoing discussion is applicable to the 
raising of early lambs. If, however, they are dropped 
during the grazing season, where the ewes have abun- 
dant pasturage, the question of feeding is simplified, for 
no ration is more promotive of abundant milk secre- 
tion than young grass; besides, the low price at which 
late lambs are usually sold does not encourage exten- 
sive grain feeding. When lambs are grown for breed- 
ing stock their early grain rations should be lighter, 
and may properly consist more largely of oats and 
bran, with a smaller proportion of corn. 

FEEDING COLTS 

The value of a horse for either draft or road pur- 
poses is greatly dependent upon those physical qualities 
which secure vigor and endurance. A horse is not 
regarded as desirable that is devoid of "nerve" and 
that cannot sustain, if necessary, the strain of hard, 
or even severe, work; and breeders seek to produce 
animals having these characteristics. Two main factors 
are involved in the proper physical development of 
the colt: food and exercise. The latter is a part of 
the general management to which the horse breeder 
must give detailed attention and will not be discussed 
in this connection. The technics with which the 



334 The Feeding of Animals 

horseman should be familiar must be learned through 
experience and by consulting special literature. 

It is proper to state that our knowledge concerning 
the feeding of colts consists largely of the conclusions 
derived from experience of practical men. Very little 
experimental attention has been given to this subject 
by investigators. During the twenty -five years that 
experiment stations have existed in the United States 
only two stations have reported experiments along this 
line, and these were not extensive; but notwithstanding 
the lack of direct data from scientific sources there are 
well proven and safe facts to which we can refer. 

Feeding the dam. — The proper feeding of the young 
foal is accomplished first through the proper feeding 
of the dam. The mare with a colt at her side should 
be regarded as a milch animal, making demands upon 
the food for generous milk production similar to those 
made by the milch cow. This is equivalent to the 
statement that when suckling her foal the dam should 
be given foods that stimulate milk secretion. If she 
is allowed the run of a good pasture both mother and 
colt will usually thrive satisfactorily. Young pasture 
grass is as efficient with the mare as with the cow. 
If, on the other hand, the feeding is from the stable, 
either wholly or to amend an insufficient or inferior 
food supply from grazing, then the grain ration should 
be made to include such feeding stuffs as barley, oats, 
wheat, wheat bran, wheat middlings, peas, and even 
a small proportion of linseed meal. Whenever soiling 
crops are grown these may be fed, especially alfalfa. 
In case the legume fodders are available, either green 



Gram Foods for Colts 335 

or dried, the necessity for protein in the grain is not 
so great and corn ma}- form a larger proportion of the 
ration. 

A good grain mixture for ordinary conditions would 
be cracked corn two parts, wheat bran seven parts 
and linseed meal one part; or ground oats four parts, 
wheat middlings five parts and linseed meal one part. 

Feeding the colt. — Before the colt is weaned, with 
good management, he will learn to eat grain, which is 
very likely to be the same mixture as that eaten by 
the dam. If desired, an enclosure may be built, into 
which the colt and not the mother can pass, where a 
special grain food may be provided. This brings us 
to the consideration of what shall be the grain ration 
of the colt, both before and after weaning. 

The opinion is generally held that oats are superior 
to all other feeding stuffs as horse food, particularly 
for the development of those qualities of temperament 
and muscle which are regarded as so desirable, espe- 
cially in a carriage horse. It is recognized, of course, 
that oats are comparatively costly, but it is claimed 
that the superior results, whether in the kind of devel- 
opment of the colt or in the quality of service of the 
mature animal, justify their use. An opinion so uni- 
versally entertained is not wisely ignored. It has been 
shown many times, however, that popular views have 
been wholly or in part erroneous, or, at least, have 
been based upon wrong premises; and in this partic- 
ular case certain statements are currently accepted as 
facts which have no well-established basis. 

Reference is frequently made to the tonic effect of 



336 . The Feeding of Animals 

oats, and there appears to be a popular notion abroad 
that this grain contains a peculiar compound which 
acts as a nerve stimulant and imparts " life " to the 
horse. 

No chemical facts to support this view can be cited. 
To be sure, it was announced in 1883 that Sanson had 
discovered in oats a characteristic alkaloid having a 
stimulating effect upon the motor nerves of the horse, 
but subsequent elaborate investigations by Wrampel- 
myer failed to verify Sanson's conclusions. Notwith- 
standing the fact that the oat kernel has been the 
subject of very careful chemical studies, no chemist 
has yet discovered that it contains any compounds so 
characteristically unlike those of other grains as to 
account for an unusual influence upon the nervous 
system, or for a superior development of the muscles. 

There does not appear to be on record testimony 
of a more convincing character concerning the stimu- 
lative influence of oats than opinions, partly traditional 
and partly the result of not very exact practical obser- 
vations. While it is certainly not easy to present a 
definite and satisfactory explanation of the existence of 
these opinions, it may be suggested that the "life," or 
nervous condition, of a horse is a resultant of several 
factors or influences. These are the quantity of diges- 
tible food supplied, the proportion of protein in the 
ration, the condition of the digestive tract, care, exer- 
cise, and all the many small influences which affect 
health. In those instances where feeding oats has 
seemed to improve the performance of the horse, even 
if this has actually occurred, we have no assurance 



Oats vs. other Grains 337 

that in changing the ration the amount and proportions 
of the nutrients digested have remained the same. It 
is probable that usually comparisons have been made 
between oats and corn, and whenever this has been 
done it is not necessary to refer the better effect of 
the former to the existence of compounds having tonic 
properties. The well-known differences in the gen- 
eral composition of the two grains will in part account 
for the more satisfactory condition of the animal when 
the oats are fed. With the liberal feeding of corn 
there is a tendency towards the laying on of fat, and 
a greater likelihood of imperfect digestion, because of 
the high proportion of carbohydrates and the liability 
of undesirable fermentations. It seems entirely prob- 
able that if thorough comparison could be made be- 
tween oats and the best grain mixtures which could 
be suggested in the light of present knowledge, the 
oats would not maintain so great a superiority over 
other feeds for growing colts as is now generally at- 
tributed to them. The few experiments which have 
been made indicate that for producing rapid growth 
oats were inferior to either a mixture of peas and 
middlings, or to a mixture of middlings, gluten meal 
and linseed meal; but these observations were not 
carried far enough to determine the relative effect upon 
the quality of the animal. 

Whatever may be the whole truth in this matter, 
doubtless all necessary conditions for producing growth 
and quality in colts would be met by a ration of which 
oats form a part. The following mixtures are sug- 
gested as illustrative of good ones: 



338 The Feeding of Animals 

Mixture 1 Mixture 2 
Oats 4 parts Corn 2 parts 

Bran or middlings . .4 parts Oats 4 parts 

Peas 2 parts Bran 3 parts 

Oil meal 1 part 

These mixtures are generally less expensive than 
oats alone, and in kind fully meet the demands for 
growth of both bone and muscle. 

Henry gives as a fair allowance of grain for a colt, 
measured in oats, the following quantities: Up to one 
year of age, two to three pounds; from one to two 
years, four to five pounds; from two to three years, 
seven to eight pounds. In using the other grain feeds 
suggested, which mostly have a higher rate of digesti- 
bility than oats, no larger quantities would be neces- 
sary. Skim milk may be fed to colts in limited amounts 
with good results, as experiments show. Feeding it 
in quantities sufficient to force rapid growth is to be 
deplored. 

It is generally conceded that the colt should be 
allowed to eat a reasonable proportion of coarse feed 
as a means of properly developing the digestive tract. 
It is entirely possible to supply concentrated grains 
too freely, to the exclusion of more bulky materials, 
and in that way fail to secure a desirable distension of 
the alimentary canal. This does not mean that the 
colt should be allowed to gorge himself with hay or 
other coarse material, as an unfortunate extreme in 
this direction is easily reached. 



CHAPTER XXIII 

FEEDING ANIMALS FOB TEE PRODUCTION OF MEAT 

The production of beef was at one time a source 
of income to nearly all farms. In earlier days the New 
England farmer annually sent to the market a few fat 
steers or oxen. At the present time the beef consumed 
in the United States and that exported comes very 
largely from the wide grazing areas of the west-, where 
the cost of feed and the necessary amount of labor 
are at a minimum. The reasons for this change are 
not hard to find. The food cost of beef -making is 
relatively large as compared with dairy products, and 
in the east the growth of home markets for milk and 
cream has made it possible for farmers to turn their 
high cost feeding stuff into products having a higher 
proportionate market price than beef. Moreover, cer- 
tain eastern lands have, with enlarging markets, been 
occupied to good advantage with fruit and vegetables. 
Doubtless the time will come, after the wide areas of 
the west are more densely peopled, when beef produc- 
tion will receive more attention in the eastern states. 
Some farmers find it profitable there even now. It is 
certain that it involves good judgment, skill and the 
art of feeding to the highest degree, especially if it 
is to secure fair returns against western competition. 

(339) 



340 The Feeding of Animals 

The breeding or selection of animals of the most prof- 
itable type that will supply the market with a high- 
grade product, and stable feeding, so as to produce 
rapid and continuous increase without disease or disas- 
ter of any kind, require experience and an intelligent 
application of all the factors involved. 

THE NATURE AND EXTENT OF THE GROWTH IN BEEF 

PRODUCTION 

Feeding steers or oxen for the market may be car- 
ried on with young animals that are still making some 
growth of bone and muscle, or with those so mature that 
additional weight comes almost wholly from a deposi- 
tion of fat in the tissues already formed. This is the 
difference between feeding a two -year -old and a five- 
year-old steer. In either case the predominating con- 
stituent of the increase is fat. This fact is established 
by the investigation of Lawes and Gilbert and by one 
experiment in this country. Dr. Gilbert in his lec- 
tures summarizing the Rothamsted work gives the 
following figures: 

Composition of increase when steers are fattening 

Water Ash Protein Pat 

% % % % 

Oxen fattened very young 32-37 2% 10 50-55 

Matured animals, final period 25-30 1% 7-8 60-65 

American results with well-fed 
steers, growth from 17 mos. to 
27 mos. of age 42.4 6. 14.1 37.5 

These figures may be regarded as reliable, and they 
show most conclusively that in beef production the 



Food Needs of Fattening Steers 341 

constructive use of the food is largely in the direction 
of fat -forming. 

The extent of the actual production which occurs 
can be closely estimated for any given case. It is 
considered satisfactory if the rate of increase during 
a reasonably long period of fattening is 2 lbs. live 
weight per day. This means the actual addition to 
the dry substance of the body of from 1.3 to 1.5 lbs. 
Sometimes during short periods with excessive feeding 
the daily gain may be 3 lbs. live weight, and generally 
after animals are well fattened, during the finishing 
period, it may be as low as 1 lb. or less. The actual 
daily growth of new material may vary then, aside 
from the water, from .6 to 2.25 lbs. per day. Actual 
fat formation may thus range from .4 to 1.8 lbs. per 
day. The proteid content of the increase, on the other 
hand, probably does not exceed .3 lb. daily in any in- 
stance, and with mature animals it is very insignificant. 

The food needs of the fattening steer. — In view of 
the foregoing facts and of the prevailing views as to 
the fat -forming function of carbohydrates, we can but 
conclude that the non- protein part of the ration may 
be the source of the chief part of the body substance 
laid on by a fattening steer. The amount of protein 
necessary for constructive work seems to be very small 
— with mature animals it is practically nothing. Our 
theoretical point of view as to the nutrients which will 
serve the purposes of a fattening animal is therefore 
quite different from what it was when eminent author- 
ities regarded protein as the main source of bodj^ fat. 
It would seem, looking at the matter merely from the 



342 The Feeding of Animals 

standpoint of the demands for growth, that in feeding 
fairly mature animals for beef production a ration may 
be efficient with a wide nutritive ratio, much wider than 
what is recommended in the German standards. 

It is recognized, though, that we cannot decide upon 
a ration merely upon the basis of the raw materials 
that are needed for constructive purposes. The influ- 
ence of a particular feed or of a variety of feeds upon 
the appetite and upon what we speak of as general 
condition, as well as upon the quality of the product, 
and the necessity of avoiding so large a preponderance 
of carbohydrates as to cause a possible depression of 
digestibility are all points which must be considered 
iti determining the value of a ration. We should re- 
member also that the stimulating effect of the food 
upon the vital functions is a factor in successful feed- 
ing. So, after all, we must appeal to experience, scien- 
tific and practical, for information as to what rations 
are efficient for fattening purposes. 

The German standard rations for fattening bovines 
which are at present recommended call for 18 to 18.4 
lbs. of digestible organic matter daily for each 1,000 
lbs. of live weight, with a ratio of 1:5.4 to 1:6.5, 
requiring from 2.5 to 3 lbs. of digestible protein. If 
protein was regarded as taking a prominent part in 
fat-building and in sustaining muscular activity, as 
was once held, this standard might seem rational, but 
in view of more recent scientific conclusions concern- 
ing the functions of nutrients it is not easy to under- 
stand why a fattening steer requires more protein than 
a milch cow or even as much. 



Proportion of Protein in Fattening Ration 343 

It is gratifying to discover that feeding experi- 
ments with fattening oxen, conducted under the im- 
proved methods of research, give results not inconsist- 
ent with the facts to which attention has been called. 
Kellner very ably discusses a large number of such 
experiments, made by himself and associates with the 
aid of the respiration apparatus, and he emphatically 
declares that the nutritive ratio of a fattening ration 
may vary from 1:4 to 1:10 without affecting the 
increase of body substance from a unit of digestible 
food material, provided, however, that the nutrients 
supplied above maintenance needs shall come from 
the more easily digestible feeding stuffs. He cites, in 
the support of his conclusion, the outcome of nineteen 
previous experiments by Wolff, in which rations va- 
rying in nutritive ratio from 1:4 to 1:9.5 showed 
no material differences in the efficiency of a unit of 
digestible matter. It seems, then, that scientists are 
coming to agree that a wide nutritive ratio is not 
inconsistent with most successful feeding of fattening 
steers, especially those that are mature. If the ani- 
mals are so young as to be making material growth, 
then it is conceded that there is more reason for avoid- 
ing a very wide ratio. 

Among the practical feeding experiments conducted 
in the United States, there are several instances where 
the wide ratio rations have been found equal to the 
more nitrogenous. On the other hand, and perhaps 
in a majority of experiments, the rations containing 
the largest proportion of protein have caused the most 
rapid growth. In 1893 the writer made a careful study 



344 The Feeding of Animals 

of man j- previous experiments, and found that the 
addition of some highly nitrogenous feeding stuff to 
corn meal, or other home-raised grain, in most instances 
increased the productive power of the ration. This 
fact stands in apparent conflict with the more scientific 
conclusions to which reference has been made. The 
probable explanation of this discrepancy is that the 
rations richest in protein have generally contained the 
greater variety of feeding stuffs, have been more palat- 
able, more stimulating to the appetite, and, in general, 
have caused a more vigorous exercise of the animal's 
functions. The proportion of protein has probably 
been a minor factor. If as great a variety of as pal- 
atable and as easih' digestible materials can be fed 
without the use of highly nitrogenous feeding stuffs 
as with them, the result will doubtless be just as favor- 
able. This means that a mixture of home- raised grains 
may form as efficient a ration for fairly mature fatten- 
ing steers as when the oil meals or gluten meals are 
introduced. Palatableness, variety and ease of diges- 
tion are the main points to be secured, and these fac- 
tors have been somewhat overshadowed by the effort 
to secure merely a definite relation of protein to car- 
bohydrates. 

It need not be feared that when mixed cereal grains 
are fed as the major part of the ration, there will be 
a materially lower rate of digestibility than when a 
protein food is introduced. There is still something 
to be said, however, in favor of adding to a fattening 
ration a small proportion of an oil meal, or of some 
material of similar character, for palatableness is thus 



Feeding Standard for Fattening Steers 345 

promoted, and observations show, in many instances, 
that an appearance of greater thrift and vigor is thus 
induced, which is probably due to the stimulating effect 
of the greater amount of circulatory protein upon the 
metabolic processes of the animal. With young steers 
making some growth of bone and muscle, a small 
quantity of a protein food is of unquestioned advantage. 
The German standard for fattening cattle is open 
to criticism as to the quantity of nutrients recommended 
for 1,000 lbs. of live weight. In order to supply 18.4 
lbs. of digestible organic matter it would be necessary 
to feed, for instance, 8 lbs. of hay and 21.5 lbs. of an 
ordinary mixture of corn meal, bran and oil meal. 
While it ma}- be possible to induce young steers weigh- 
ing from 600 to 800 lbs. to eat at this rate for a short 
time, so large a ration is seldom, if ever, so profitable 
as a smaller one, even if it could be fed with safety. 
If an attempt was made, however, to appty this form- 
ula to mature steers weighing from 1,300 to 1,500 lbs. 
the situation would become absurd, because the ration 
would then be from 10.5 to 12 lbs. of hay and from 
25 to 32 lbs. of mixed grains for a single animal. 
An appeal to concrete examples of steer feeding will 
clearly show the excessive requirements of the German 
standard for fattening cattle. In 1891 to 1893 the 
Kansas Agricultural Experiment Station conducted 
feeding experiments with three -year -old steers, and 
as these are good examples of practical management, 
the data from them will serve to illustrate the point 
under discussion. These data are stated in a tabular 
form : 



346 The Feeding of Animals 

1st Expt. 2d Expt. 

Number of animals 5 3 

Days fed 182 129 

Weight per animal, average for period 1,412 lbs. 1,237 lbs. 

Hay eaten per day 7.8 " 6.7 

Grain eaten per day 23.9 " 23. " 

Daily gain per animal 2.39" 2.4 

Digestible organic matter daily per animal 19.5 " 19. 

Digestible organic matter per 1,000 lbs. live weight 13.8 ' 15.3 

In 1895-6 the Iowa Agricultural College fed steer 
calves for fourteen months, during ten of which a 
record was kept of all the food consumed. During the 
second period the steers were fattened for market. 
This particular experiment is cited because the animals 
were young and all the conditions were favorable to 
the maximum consumption of food in proportion to 
live weight: 

1st period 2d period 

Number of animals 5 5 

Days fed ' 120 181 

Age of steers at beginning 9 to 10 mos. 16 to 17 mos. 

Weight per animal, average for period 766 lbs. 1,197 lbs. 

Coarse food eaten daily (partly roots and green fodder). 11 ' 12.8 

Grain eaten daily (partly snapped corn) 9 " 19.5 

Daily gain per animal 2.04 lbs. 2.11 lbs. 

Gain per 1,000 lbs. live weight 2.66 " 1.76 " 

Digestible organic matter daily per animal 10. 14.1 

Digestible organic matter daily per 1,000 lbs. live weight. 13. 11.8 

The largest amount of digestible nutrients fed daily 
per animal at anj* time during this experiment was 
about 17.5 lbs., after the animals had reached an 
average weight of 1,200 lbs. or over. This would be 
approximately 14.5 lbs. digestible organic matter per 
1,000 pounds live weight. 

These two experiments are instances of successful 
feeding where the increase was rapid and very satis- 



Ration for Fattening Steers 347 

factory, and where the quantity of digestible nutrients 
supplied daily was greatly below 18 lbs. per 1,000 lbs. 
live weight. 

Many other feeding trials might be cited in illus- 
tration of the unpractical character of the German 
standard, when accepted without modification. 

The writer is led to conclude, from observation and 
a study of the results of experiments, that under proper 
conditions 8 to 10 lbs. of dry coarse food and 15 to 
18 lbs. of grain is all that can generally be fed with 
greatest profit to a steer actually weighing 1,000 lbs., 
and may be even more than is utilized by the animal 
to the best advantage. Such a ration would supply 
about 16 lbs. of digestible organic matter. If consid- 
erably smaller steers are fed the ratio of food to weight 
may be increased, but if the animals are several hun- 
dred pounds heavier the ratio must be materially dimin- 
ished. It is safe to accept as a general principle the 
rule that the larger the animal the less the proportion 
of food to weight. The fixing of the quantity of a 
fattening ration directly in proportion to the size of 
the animal is a simple and quite convenient rule, but 
is utterly impracticable, and is so recognized at present 
in the standards for growing animals and should be 
in all estimates and proportions. 

THE SELECTION OF A FATTENING RATION 

Two conditions alreadj^ mentioned that are of the 
highest importance should not be forgotten; viz., that 
the ration should be palatable and be composed of a 



348 " The Feeding of Animah 

variety of easily digestible materials. Rough fodder 
in any quantity is not adapted to fattening bovines. 
With this exception, the whole list of high -class cattle 
foods may be regarded as available, and the selection 
will properly depend largely upon prices and the local 
supply. In the northern states, hays from the fine 
grasses and the legumes, silage, roots, cereal grain 
mixtures and such by-product feeding stuffs as offer 
digestible nutrients at the least cost will all appeal to 
the experienced feeder. In the south, cottonseed by- 
products may, with economy, enter largety into the 
ration. In the west, the fodders peculiar to that re- 
gion will be utilized, corn being the chief, and some- 
times the only, grain that can be fed with economy. 
The following may be regarded as good types of mix- 
tures for the full feeding of fattening steers weighing 
approximately 1,000 lbs. each at the beginning of the 
feeding period. They will supply about 16 lbs. of 
digestible organic matter if their components are of 
average quality and composition: 



5 lbs. clover hay. 
I 16 lbs. corn silage. 
I 13 lbs. corn meal. 

3 lbs. wheat bran. 



8 lbs. alfalfa hay. 
12 lbs. corn meal. 
5 lbs. ground oats. 



10 lbs. corn stover. 5 lbs. clover hay. 

i 20 lbs. mangels. p. I 50 lbs. beet pulp. 

1 14.5 lbs. corn meal. Ill lbs. corn meal. 

[ 2 lbs. cottonseed meal. ^ 2 lbs. cottonseed meal. 

8 lbs. mixed hay. 8 lbs. corn stover. 

12.5 lbs. corn meal. 6 -I 12.5 lbs. corn meal. 

3 lbs. wheat bran. [ 20 lbs. brewer's grains, wet. 
2 lbs. oil meal or gluten f d. 



Rations for Steers — Mutton Production 349 



2 lbs. oat straw. 
75 lbs. beet pulp. 
10 lbs. beet molasses. 

4 lbs. gluten meal. 



5 lbs. alfalfa hay. 
3 lbs. corn stover. 

11 lbs. corn meal. 

6 lbs. ground barley. 



5 lbs. mixed timothy and clover. 
30 lbs. silage. 
13 lbs. oats and peas. 

The above rations are well up to the quantity limit 
for the profitable feeding of animals weighing approxi- 
mately 1,000 lbs. They are simply illustrative, how- 
ever, both in kind and in quantity. Many mixtures 
equally efficient may be used, and the quantity of 
the ration must vary not only with the age and size 
of the animal but with individuals, according to ap- 
petite and capacity. Any feeder of experience will 
understand, of course, that such rations will be eaten 
with safety to the animal only after a period of pre- 
liminary feeding, during which there has been a grad- 
ual increase in the quantity of food offered. 

MUTTON PRODUCTION 

Attention has been called to the fact that beef pro- 
duction in the United States has gravitated to the 
extreme west. This is also true of the production 
of mutton, though not to the same extent. Flocks 
of sheep are still kept on many farms of the eastern 
and middle -west states, and the growth of early lambs 
and the fattening of maturer animals to supply the 
demands of the local markets is found to be most 
profitable by those farmers who possess the knowledge 
and skill requisite for this branch of stock husbandry. 



350 The Feeding of Animals 

Sheep occupy a peculiar place on the farm in that 
they will accommodate themselves to pasturage that 
is not adapted to cows and horses, and will utilize 
some kinds of rough fodder not readily eaten by other 
farm animals without submitting it to somewhat ex- 
pensive methods of preparation. If it were not for 
the discouragement which sheep husbandry has received 
from the depredations of dogs, sometimes real and 
sometimes greatly overestimated or even imagined, 
the production of wool and mutton would greatly in- 
crease on the hill farms of this country, with undoubted 
profit to eastern agriculture especially, where soil fer- 
tility needs strengthening in every possible way. 

THE NATURE AND EXTENT OF THE GROWTH IN FAT- 
TENING SHEEP 

The character of the animal that is fattened for 
mutton varies within wider extremes than in steer 
feeding. This is due chiefly to the greater range in 
maturity of. the former, from the two months' lamb to 
the mature wether. There are corresponding differences 
in the nature of the increase while fattening, accord- 
ing as the animal is young and making growth of all 
parts of the body or is simply storing fat in the mature 
organism. The character of the body substance stored 
probably is also influenced by the stage in the fatten- 
ing period, whether at the beginning when the animal 
is thin or near the end when a fat sheep is becoming 
fatter. The only definite data which can be presented 
relative to the composition of the increase of fattening 



Character of Increase of Fattening Sheep 351 

sheep are based upon the analyses by Lawes & Gilbert 
of animals in various states of fatness. These inves- 
tigators analyzed a "store" sheep, a "fat" sheep and a 
"very fat" sheep, and from the figures thus obtained 
are calculated the increase in two stages of fattening: 

Composition of increase of fattening sheep 

Dry 

substance Ash Protein Fat 

% % % % 

Increase from "store" to "fat" condition.. 78. 2.12 7.16 68.8 
Increase from "fat" to "very fat" condition. 81. 8 3.12 7.75 70.9 

A comparison with the increase of fattening oxen 
shows that the sheep stores the larger proportion of 
fat in the dry substance laid on. 

Sheep liberally fed give a larger increase per 1,000 
lbs. live weight than steers. With animals weighing 
from 75 to 150 lbs. each the daily gain with good 
management may range from .2 to .5 lb. per head, 
or from 2 to 5 lbs. per 1,000 lbs., live weight, the 
increase varying according to age, conditions and lib- 
erality of feeding. Lambs will sometimes greatly ex- 
ceed the above maximum. If we base our estimates 
upon what will occur with the maturer animals, a num- 
ber of lambs or sheep weighing 1,000 lbs., perhaps 
seven, perhaps twice as many, will store daily .15 to 
.40 lb. of protein and from 1.4 to 3.5 lbs. of fat. 

FOOD NEEDS OF FATTENING SHEEP 

After long -continued and careful experiments in 
feeding a fattening ration to mature sheep, whose 
composition was investigated at various stages of 



352 The Feeding of Animals 

fatness, Henneberg concludes that the very small 
amount of muscle tissue laid on by such animals may 
be ignored. Pfeiffer reached the same conclusion from 
experiments with the same class of animals. This 
view would not hold with lambs during their increase 
from weaning time to 100 lbs. in weight, for in this 
period there must be a material and continuous storage 
of nitrogenous tissue. 

As is the case with steers, the demand for protein 
storage is seen to be small with mature fattening sheep, 
the constructive use of the ration being largely directed 
to fat formation. The more recent views of the func- 
tion of the nutrients allow us to believe that, as with 
bovines, carbohydrates and perhaps fats play a leading 
part in supplying raw materials for the carcass increase. 
There is one point of difference between steers and 
sheep, however: viz., the growth of wool with the lat- 
ter, that requires the use of more or less food protein. 

The German standard for fattening sheep is 18.5 
to 18.6 lbs. of total digestible organic matter per 1,000 
lbs. live weight, 3 to 3.5 lbs. of which shall be protein, 
thus giving a nutritive ratio ranging from 1:4.5 to 
1:5.4. There is little doubt that this standard calls for 
an unnecessarily large proportion of protein. Neither 
scientific facts nor the observations of practice justify 
the conclusion that sheep will fatten faster when pro- 
tein is so liberally supplied than when properly com- 
pounded rations with a wider nutritive ratio are fed. 
Doubtless more regard should be paid to the protein 
supply with sheep than with steers, but it is difficult 
to adduce a single argument for insisting upon so 



Feeding Standards for Fattening Sheep 353 

narrow a nutritive ratio with any species of fattening 
animal, unless it becomes incidental to an economical 
purchase of feeding stuffs. We may safely conclude 
that the resources of the farm are sufficient to supply 
enough protein for a ration of an efficient character 
for the class of animals under consideration, though 
we should give due recognition to the fact that, with 
fattening lambs especially, the protein feeding stuffs 
may be most efficiently utilized. 

The quantity of nutrients prescribed by the pub- 
lished standard for fattening is practically the same 
per unit of weight as that given for fattening bovines. 
This runs contrary to common observation and the 
results of experiments. The standard for steers has 
been characterized as excessive, but this fault cannot 
be charged to the one for sheep, for, if anything, it is 
below the demands of practice. Even mature sheep about 
average size will consume 18.5 lbs. of digestible nutri- 
ents per 1,000 lbs. live weight, but this ratio does not 
meet the requirements for the prevalent intensive feed- 
ing of lambs and yearlings weighing from 75 to 125 
lbs. each. It is easily demonstrable not only that sheep 
will utilize a proportionately larger quantity of food 
than bovines, but that they will make a relatively 
greater increase. The results of two experiments in 
fattening wether lambs, reported from the Iowa Agri- 
cultural College in 1896 and 1897, when compared with 
the outcome of steer -feeding trials, serve admirably to 
illustrate the correctness of this statement. The lambs 
were divided among seven mutton breeds. Sixty-nine 
were fed 90 days and 64 others were fed 107 days. 

w 



354 The Feeding of Animals 

The main facts derived from these feeding trials 
are as follows: 

Number of animals 133 

Average days fed 98.2 

Total average weight of animals 16,400 lbs. 

Average weight single animal 123 " 

Dry matter consumed 51,000 " 

Digestible organic matter consumed 34,500 " 

Dry matter eaten daily per 1,000 lbs. live wt. . . 31.8 " 
Digestible organic matter eaten daily per 1,000 

lbs. live weight 21.5" 

Daily gain per 1,000 lbs. live weight 3.73 lbs. 

Daily gain per animal .467 ' ' 

The food consumption in this instance of the suc- 
cessful fattening of lambs is considerably in excess of 
the German standard; and the amount of food con- 
sumed is not unusual, though it is stated that in the 
latter stages of the experiments the animals were 
crowded to their full capacity. 

If a comparison is made of this experiment with 
the steer feeding experiments previously cited it be- 
comes clearly evident that the published feeding stand- 
ards are not consistent in calling for practically the 
same quantity of nutrients for the same live weight 
of the two species. Sheep will consume at least one- 
quarter more food than steers and lay on flesh propor- 
tionate^ faster. Moreover, sheep appear to make a 
larger gain in live weight than steers for each unit of 
nutrients consumed. It may be that the testimony of 
the experiments cited relative to the points under 
discussion is not a correct expression of the average 
conditions, but the differences shown are too marked 



Rations for Fattening Sheep 355 

to be accounted for by any unusual conditions pertain- 
ing to these feeding trials, and therefore indicate what 
may generally be expected in practice. 

THE SELECTION OF A RATION FOR SHEEP 

The range of feeding stuffs from which a sheep 
ration may be selected is wide and includes practically 
all home -raised fodders and grains and the whole list 
of by-products. It cannot be said, though, that all 
materials are equally desirable as sheep food. Of the 
fodders, those from the legumes are especially to be 
sought, even pea and bean straws, and among the 
grains corn stands preeminent as the basis of a fat- 
tening ration. Probably no feeding stuffs are more 
favored for mixing with corn than oats, bran and 
linseed meal, probably because none are more success- 
fully used. Barley, peas, beans, gluten feed, gluten 
meal and cottonseed -meal have also been successfully 
fed to sheep. A mixed grain ration is unquestionably 
to be preferred to any single grain or by-product, be- 
cause with the mixture greater palatableness is insured, 
it is possible to maintain the consumption of a larger 
ration, and the danger to health of heavy feeding is 
less. The selection of the components of the grain mix- 
ture should be governed somewhat by market prices. 
A supply of silage or roots is much to be desired as 
a part of a sheep - fattening ration, especially when 
heavy grain rations are to be fed during a long period, 
although successful feeding during a limited time is 
entirely possible without these. A succulent food 



356 The Feeding of Animals 

promotes appetite and health, however, and is usually 
economical and sometimes necessary. 

Rations made up in definite quantities will not be 
presented in this connection. The quantity of nutri- 
ents which it is desirable to supply is so variable 
according to the age and maturity of the animals to 
be fattened that a feeding standard is applicable to 
only one set of conditions not long maintained and 
therefore it must be freely and frequently modified 
according to the judgment of the feeder. It is, nev- 
ertheless, possible to offer practical suggestion as to 
the proportions of grains in the mixtures that will be 
found acceptable and as to the kinds and quantities 
of coarse foods ordinarily utilized. 

In the Iowa experiments cited in this connection 
the grains used were corn, oats, bran and linseed meal. 
In the last of these trials the grain ration for fifteen 
daj r s at first was made up of corn, oats and bran in 
the proportions 2, 2 and 1. When the feeding was 
well established the grains were oats, corn, bran and 
oil meal, the relation in quantity being 8, 8, 2 and 1 
respectively. Each animal ate about 1 pound of roots 
daily and about two -thirds as much hay as grain. 
The lambs were fed up to the full ration very grad- 
ually, several weeks being occupied in doing this. For 
such preparatory feeding bran and oats are especially 
useful. When these tests began, each animal ate from 
one and a half to two pounds of grain daily, which 
quantity was increased later to three pounds with the 
largest eaters, some individuals not taking over two. 
The conduct of these feeding trials typifies good prac- 



Foods for Fattening Sheep — Feeding Swine 357 

tice, both as to materials and management, and may 
serve as a guide in handling other similar feeding stuffs. 

It is undoubtedly possible to feed sheep with equal 
success without the use of purchased grains, especially 
on farms where clover or alfalfa, roots, corn, oats, or 
oats and peas are produced. We are not justified by 
experimental results in concluding that bran and oil 
meal or any other by-product feeds are essential to 
the highest success in fattening sheep, although these 
feeding stuffs are very useful for this purpose. A 
mixed grain ration is always better than any single 
grain fed alone. 

Instances are on record of a successful combination 
of green forage crops with grain in fattening sheep. 
The legume fodders and rape may be fed profitably in 
the green state with the usual grain mixtures, care 
being taken to avoid indigestion from excessive eating 
of the green material. 

Grain in connection with ordinary pasturage is a 
successful method of fattening sheep or lambs for the 
fall market. 

PORK PRODUCTION 

The feeding of swine is a matter of almost univer- 
sal interest to farmers. Even in the older portions 
of the east a few animals of this class are kept on 
nearly every farm. Swine are well adapted to the dis- 
posal of certain wastes, particularly those from the 
table and the dairy. They are especially useful as a 
means of profitably converting dairy by-products into 
a marketable form, and, moreover, during the past 



358 The Feeding of Animals 

twenty -five years pork production has offered more 
encouraging inducements to the home consumption of 
grain than has beef production. 

Within recent years there has been a great change 
in the methods of pig feeding and in the character of 
the animal when placed upon the market. This is 
emphatically true of the eastern and middle states, 
where pork is grown wholly for local consumption. 
Formerly good feeders were not supposed to slaughter 
a pig under three hundred pounds carcass weight, 
and many animals dressed four hundred pounds when 
taken to the market, this size being secured only after 
a feeding period of twelve to eighteen months. Pork 
of this character was regarded as well adapted to pack- 
ing. At the present time the demand of the local 
markets is for small carcasses weighing not over one 
hundred and fifty pounds, and supplying the maxi- 
mum proportion of lean cuts. This change is in the 
direction of greater profits for the farmer, as he has 
learned, because the food expenditure required for the 
production of small carcasses is much less per unit of 
weight than under the old system, when the feeding 
was continued during a longer period. Pigs properly 
fed are now wisely turned off at the age of a few 
months, excepting, perhaps, in those localities where a 
slow early growth is cheaply secured on pasturage. 

CHARACTER OF THE GROWTH IN PORK PRODUCTION 

The modern hog is emphatically a fat -producing 
organism, having a capacity in this particular greatly 



Character of Growth with Pigs 359 

surpassing any other species of domestic animal. The 
dry matter of the carcasses of individual animals has 
been found to consist of over 80 per cent of fat, even 
after the leaf -lard was removed, and the average pro- 
portion in the dry substance of eight dressed pigs, rep- 
resenting six breeds, was found by Wiley to be 78 per 
cent. 

The statement of the composition of a Berkshire 
pig and of a Duroc- Jersey will be found interesting in 
this connection : 

Composition of the entire dressed animal, head, leaf -lard and 
kidneys removed. Wiley. 

Weifiht Dry- 

carcass Water substance Ash Protein Fat 

% % % % % % 

Berkshire 129 43.1 56.9 2.6 13. 40.5 

Duroc- Jersey 149 30.6 69.4 1.8 9. 57.7 

Fat pig, entire animal 

(Lawes & Gilbert).. 43.9 56.1 1.9 11.9 42.3 

It appears that there was stored in the part of the 
animal analyzed by Wiley only 13 pounds of protein 
with the Duroc -Jersey and about 17 pounds with the 
Berkshire, the quantities of fat being 52 pounds and 
86 pounds, respectively. The figures for the entire 
animal, as anal}'zed by Lawes and Gilbert, are at the 
rate of 23.8 pounds protein and 84.6 pounds fat, in a 
pig weighing 200 pounds. 

These proportions bring out sharply the character 
of the growth with swine. It is to be noted that in 
no other species, very fat sheep possibly excepted, 
does the body consist so largely of dry matter, which 
means that the increase of a unit of live weight in- 



360 The Feeding of Animals 

volves the storage of more food substance than with 
other domestic animals. The data at our command 
warrant the statement, in a general w T ay, that when a 
pig gains 1.5 lbs. daily in live weight he stores not 
less than .84 lb. of dry substance, of which .18 lb. 
is protein and .03 lb. is fat, these figures representing 
the average growth during the life of the animal. 

Lawes and Gilbert estimate that the increase of pigs 
while fattening has the following composition: 



Water Dry substance 


Ash 


Protein 


Fat 


22% 78% 


.10% 


6.4% 


71.5% 



According to these figures the protein storage, with 
1.5 lbs. daily gain, would be only .10 lb. and the fat 
1.07 lbs. 

FOOD REQUIREMENTS FOR PORK PRODUCTION 

Feeding the dam. — Under a system of intensive 
production pigs go to market so young that we may 
properly discuss their feeding from birth. We deal 
first with the mother as a milch animal. According 
to observations by Henry, in an inquiry as to the 
yield and composition of sow's milk, it seems probable 
that in proportion to their weight small sows yield as 
large a quantity of milk solids daily as a good cow. 
The average daily production of milk solids per animal 
appeared to be about one pound. This would be four 
pounds for four sows, which is the equivalent of the 
solids in over thirty pounds of cow's milk of average 
quality. It follows, therefore, that the demands upon 



Food Requirements of Pigs 361 

the food for milk formation are proportionally as heavy 
with swine as with cows, and consequently the ration 
should be one that will stimulate and sustain abundant 
milk secretion. Such feeding is not only necessary, 
but economical, for independent experiments indicate 
that the food cost of the growth of pigs before wean- 
ing is no greater than it is after weaning. 

Skimmed milk or buttermilk combined with a mix- 
ture of wheat middlings and one of the ground cereal 
grains, barlej', oats or corn, cannot be improved upon 
as food for milch sows. The feeding should be liberal, 
quite up to the limits of capacity, and even then the 
dam suckling a large litter of young will grow thin. 

Feeding j)igs for the market. — If we merely consider 
the nature of the body substance of swine in its rela- 
tion to the constructive functions of the nutrients, it 
would not be unreasonable to believe that rations with 
a wide nutritive ratio are adapted to the needs of this 
class of animals for growth. In a certain sense, prac- 
tice ratines this view. Thousands of fat hogs have been 
the product of almost exclusive corn feeding, especially 
during the later stages of growth. There is no doubt 
but that large size and an excessively fat condition 
may be secured through a liberal supply of carbohy- 
drate material, but such one-sided nutrition is not 
now regarded as being adapted to the physiological 
requirements of the pig or as producing pork which 
meets the existing demands of the market. 

It is doubtful if any other species of domestic ani- 
mal has been the subject of so much abuse through 
improper feeding, combined with an unhealthful en- 



362 The Feeding of Animals 

vironment, as has the pig. We now regard the 
abnormal masses of porcine fat which have heretofore 
appeared in our markets as not only an exhibition of 
physical monstrosities, but as not serving the health 
interests of the human family. 

The primary object in feeding pigs should be, as 
with all domestic animals, the securing of a normal 
and vigorous physiological development, i. e., an or- 
ganism with a strong bony structure and with such a 
growth of muscular tissue as shall insure full exercise 
of all the vital functions. The view seems to have 
prevailed, in a practical way at least, that pigs can be 
fed on anything, live and sleep anywhere and still not 
suffer ill effects, as would be the case with the other 
farm animals. This has been unfortunate, because 
probably no other domestic species is so susceptible to 
abnormal development through improper feeding as 
are swine. It is true, at least, that no other species 
has shown so marked a response to changes in the 
character of the rations, through modifications of the 
bony structure and through variations in the propor- 
tions of muscle and fat tissue. 

Notable proof of the plasticity of the pig's organ- 
ism was supplied by the experiments of Sanborn and 
Henry in comparing rations extremely nitrogenous with 
those extremely carbohydrate in character. Pigs fed 
liberally on blood, milk and shorts combined with 
more or less corn meal, made growth more rapidly, 
had stronger bones, larger organs and more muscular 
tissue than those fed on corn meal or a mixture of 
corn meal with other highly non-nitrogenous materials, 



Food Requirements of Figs 363 

such as potatoes and tallow. The latter combination 
was deficient both in protein and in bone -forming 
compounds. Such marked differences are not usually 
seen, because rations are not generally so extremely 
one-sided. These experiments teach the lesson, though, 
that as much care should be exercised in choosing the 
pig's ration as the cow's. 

Experimental observations demonstrate that the 
pig's ration should be selected with reference to sup- 
plying an abundance of bone -making material and a 
reasonably large proportion of protein. Evidence is 
not wanting that the feeding of wood ashes and ground 
bone to growing pigs promotes both a normal develop- 
ment of the bony framework and a more liberal con- 
sumption of food. Animals that are grazing may not 
need to have the ration so supplemented, but it is 
wise and even necessary with those confined in pens. 

In selecting foods for the production of small pork 
where the development of all forms of tissue is taking 
place, first rank must be given to the dairy wastes. 
As a means of promoting rapid growth and a condi- 
tion of health and vigor, and also as a supplement to 
cereal grain products, skim -milk and buttermilk are 
not excelled, and perhaps not equaled, by any other 
feeding stuffs. In order to secure the maximum result 
from a given quantity of dairy wastes, they should be 
fed in combination with grain products. When this 
is done, and the proportions of skim -milk or butter- 
milk and grain are what they should be, it appears to 
require less digestible food substance for a pound of 
growth than when grain is fed alone or when the 



364 The Feeding of Animals 

liquid food is largely eaten. In other words, dairy 
wastes are not only efficient in themselves in producing 
growth, but in proper combination the3 r cause a saving 
of the grain products necessary to secure a given ratio 
of gain. Henry states, on the basis of eight feeding 
trials involving the use of ninety pigs, that 462 lbs. 
of skimmed milk effected a saving of 100 lbs. of corn 
meal. This means that 46.2 lbs. of digestible milk 
solids, when combined with corn meal, saved, approxi- 
mately, 76 lbs. of digestible corn meal substance. 

Henry's experiments were arranged so as to gain 
information as to the most desirable proportion of 
milk and meal, and from his data the writer has cal- 
culated the quantity of digestible nutrients required in 
each combination for one pound of growth: 

Digestible matter required 
for 1 lb. of gain 
Combination lbs. 

Mixed grains alone 3.9 

1 lb. corn meal to 1-3 lbs. skim-milk 3. 

1 " " " 3-5 " " 3.1 

1 " " " 5-7 " " 3.3 

1 " " " 7-9 " " 3.2 

These results show the greatest food efficiency with 
the minimum proportion of skim -milk. Other experi- 
ments, notably those by Linfield and Robertson, give 
similar testimony. With the former, in seven experi- 
ments, a milk and grain ration produced 1 lb. of gain 
for each 2.58 lbs. of digestible matter, the requirement 
with milk alone being 2.85 lbs. and with grain alone 
3.19 lbs. When 2 lbs. of skim -milk was fed with 
1 lb. of grain, 100 lbs. of the milk replaced 31 lbs. 



Food Adapted to Pigs 365 

of grain, but when the milk and grain were as 4 to 
1, 100 lbs. of milk only replaced 24 lbs. of grain. 

Doubtless with pigs in the earliest stages of growth 
after weaning, the proportion of milk to grain may 
well be larger than in the more mature periods, and 
in any case the ratio will naturally depend somewhat 
on the relative supply of the milk and grains. 

In the absence of dairy wastes, meat meal, dried 
blood and fish scraps may be used to supplement the 
grain products or a mixture of the more nitrogenous 
feeding stuffs with corn and barley will be found greatly 
superior to the corn or barley alone. Milk is more 
efficient with young pigs than the grain feeds rich in 
protein, but in the maturer periods the digestible mat- 
ter of certain of the latter seems to have a value not 
greatly, if any, below that of skim -milk solids. 

The protein feeds adapted to pigs are gluten meal, 
gluten feed, buckwheat middlings, brewer's waste, 
peas and middlings. The oil meals, excepting in small 
quantities, affect the health of swine unfavorably, and 
wheat bran is inferior to middlings. 

Of the carbohydrate foods, oats, barley, wheat, 
rice products, and especially corn, are all useful. 
Although the excessive corn feeding of swine is to be 
deplored, this grain is second in value to no other 
in the pig's ration, and only needs to be reinforced 
with more nitrogenous feeds in order to find a safe 
and profitable use. In the later stages of growth or 
fattening it may well form the major part of the 
ration. Probably no combination has been found 
more satisfactory for all around use than skim -milk, 



366 The Feeding of Animals 

wheat middlings and corn meal, the latter constituting 
the larger proportion of the grain food. 

At the present time much attention is given to 
forage crops for swine. Clover, alfalfa, rape, sor- 
ghum, rye and ordinary pasturage have all been found 
to be adapted to hogs. When fed with grain, eco- 
nomical and satisfactor}' production is secured. When 
fed alone the growth is so slow as to be unsatis- 
factory. In two experiments at the Wisconsin Ex- 
periment Station, one acre of rape, when combined 
with grain, proved to be equal to 2,767 lbs. of corn 
and shorts. Other observations show beyond question 
that such feeding is practicable and under some con- 
ditions profitable. Better results seem to follow when 
the pigs are allowed to graze than when the fodder 
crop is cut and fed to animals confined in pens. 



CHAPTER XXIV 

FEEDING WORKING ANIMALS 

The working animals now in use in the United 
States are chiefly horses and mules. Oxen were once 
employed extensively for farm labor and in lumbering, 
but these are rarely seen under the yoke at the pres- 
ent time, except in remote rural districts. It will be 
proper, therefore, to treat in this connection chiefly of 
horses that are used for draft and road purposes. 

The horse a machine. — In feeding a working animal 
the essential product of the food is energy to be used 
in drawing, walking or trotting. The latent food en- 
ergy is made available, as heretofore stated, by the 
oxidation of the several nutrients into the ordinary 
products of combustion, and the units of heat or work 
or other forms of kinetic energy evolved are directly 
proportional to the quantity of digested food which 
suffers combustion, just as the possible work of a 
steam engine under given conditions is proportional 
to the fuel consumption in the boiler. The establish- 
ment of fundamental relations between food and work 
requires on the one hand an understanding of the 
energy values of food, and on the other hand at least 
a general conception of the amount of work performed. 
The energy values of food have been considered and 

(367) 



368 The Feeding of Animals 

it now remains for us to ascertain what is known con- 
cerning energy consumption by a laboring animal. 

The work performed by a horse. — The labor per- 
formed by a draft or road animal, exclusive of the 
energy required for maintenance, may be regarded as 
consisting of two components; viz., the effort of mov- 
ing the load and that of moving the animal's body. 
If a horse weighiug 1,000 lbs. draws one mile a wagon 
which, with its load, weighs 1,500 lbs., 2,500 lbs. of 
matter have been moved through the distance traveled. 
In other words, a horse moves himself and his load, 
whether the load is drawn on a wagon or is loaded on 
his back. 

The exact expenditure of energy involved in both 
of these components cannot be measured directly. The 
work of drawing a load may be determined by the use 
of a dynamometer, but it can only be estimated so far 
as the body of the horse is concerned. If the latter 
factor could be calculated on the basis of simply pro- 
jecting a mass of matter through the space traveled 
it would be a comparatively simple problem. There is 
a vertical motion of the horse's body to be accounted 
for, as well as a horizontal, and the reduction of both 
to units of work is a difficult matter. If this could 
be done, our present knowledge of the food energy 
necessary for the performance of a unit of mechani- 
cal labor would allow quite definite calculations of the 
daily food needs of horses of different classes. As a 
matter of fact, the actual work accomplished by labor- 
ing animals has been to quite an extent a matter 
of estimation, and still is. 



Energy Expenditure bij Horses 369 

Chardin, a French army veterinarian, estimates that 
the average daily work performed is about 2,580 foot 
tons. Lavalard calculates that the total ordinary work 
of an army horse equals 8,500 foot tons. As stated 
by Armsby, the ordinary day's work of a horse is 
estimated at 1,500,000 kilogram meters, or 5,425 foot 
tons, this evidently meaning the mechanical labor out- 
side the motion of the body. With the knowledge we 
now possess it is possible to estimate approximately 
the actual work performed in a given case. 

It would be a good day's labor if a 1,000 -lb. horse 
travels twenty miles over a smooth, level, dirt road 
hauling a wagon with a load of 2,000 lbs. The draft 
of the loaded wagon would be not far from 100 lbs. 
A simple calculation shows that the mere moving of 
such a load the distance of one mile would be equiva- 
lent to 264 foot tons. The energy expenditure in 
walking a given distance has been measured by Zuntz, 
who ascertained the difference in oxjgen consumption 
of a horse when at rest and when traveling at a 
walk over a level road. According to these meas- 
urements, it appears that a 1,000 -lb. horse in walking 
one mile at the rate of two to three miles per hour 
would expend a total energy of 473 foot tons, 44.4 
per cent or 201 foot tons of which belong to the 
effort of walking over and above the energy needed for 
mere maintenance. In the case assumed, a horse would 
perform a total labor in walking and drawing twenty 
miles equivalent to lifting 9,300 tons through a space 
of one foot. This estimate is presented merely as an 
approximation of the work done under given conditions. 

x 



370 The Feeding of Animals 

These figures are, perhaps, less important to the 
owner of work or driving horses than is a knowledge 
of the influence of speed upon the labor expended in 
a unit of time. "According to Marcey, the work 
accomplished in a given time is proportionate to the 
square of the velocity. His coefficients were 3.42 for 
walking or pacing, 16 for trotting, 28.62 for canter- 
ing, and 68.39 for a full gallop." This general fact 
would be applicable to horses under all conditions of 
labor. Moreover, it is clearly demonstrated bj r two in- 
vestigators that the food energj r required for a unit of 
work increases with the speed. In other words, a 
horse that trots 20 miles a day must have more food 
than when he walks the 20 miles. In the same way 
draft animals require food somewhat in proportion to 
the pace with which they travel over a given distance. 
Grandeau has shown that a horse was kept in condition 
with 19.4 lbs. of hay when he walked 12% miles, but 
24 lbs. was insufficient when he trotted the same dis- 
tance. Zuntz measured the oxygen used per meter 
kilogram when a loaded horse traveled at different 
velocities. When the pace was three miles per hour, 
with a load of 275 lbs., the energy required was equal 
to 4,600 calories for each kilogram meter of horse, 
which increased to 7,753 calories when the speed reached 
6% to 7% miles per hour. The food needed per unit 
of work increased nearly 70 per cent in increasing the 
speed from 3 miles to 7 miles. Zuntz shows that if a 
horse exerts himself to the utmost the use of oxygen 
rises at a rapid rate, and that the food consumed per 
unit of work is nearly one -half more than with ordinary 



Food Needs of a Working Horse 371 

draft. It appears to be a rule that as the intensity 
of exertion of the horse increases the food cost of a 
given amount of labor performed increases. Men of 
experience recognize this fact in a general way when 
they insist on favoring their animals to the slowest 
pace that is consistent with the conditions involved. 

The food requirements of a working horse. — There 
are two general ways of ascertaining the food needs of 
a working horse, by practical experiments in which the 
rations are varied until a conclusion is reached as to 
what will support an animal under given conditions, 
and by determining through scientific investigations 
the amount of work performed in various ways and 
the relation of a unit of food to a unit of work. It 
would not be far from the truth to state, however, that 
the feeding standards which are offered to us through 
investigations made by Boussingault, Wolff, LeClerc, 
Grandeau, Hoffmeister, Lavalard, Zuntz, Kellner, and 
others, are the outgrowth of both practical observations 
and scientific research, a most desirable combination. 
In a large number of instances the kind and quantities 
of digestible food consumed daily by working horses 
have been determined, and in many cases the accom- 
panying wastes and gain and loss of the animal body 
have been measured. 

The standard rations now found in German tables 
are the result of such observations. According to 
these standards a 1.000-pound horse requires 11.4 lbs. 
of digestible food daily when doing moderate work, 
13.6 lbs. for average work, and 16.6 lbs. for heavy 
work. With a basal ration of 10 lbs. of hay the grain 



372 The Feeding of Animals 

needed to furnish these quantities of digestible nu- 
trients, when consisting" of a mixture in equal parts 
of corn and oats would be approximately 11.5 lbs., 15 
lbs., and 20 lbs. for the three conditions of labor. 
Lavalard, who made observations covering a period of 
a number of years for 32,000 omnibus, army, and draft 
horses, has reached the conclusion that "a horse per- 
forming ordinary work requires 115 grams of diges- 
tible protein and 1,100 grams of digestible carbohy- 
drates per 100 kilograms live weight." This is at the 
rate of 1.215 lbs. of digestible nutrients per 100 lbs. of 
live weight. This observer bases the ration upon the 
weight of the animal, but practically concedes that 
"somewhat larger amounts of protein and carbohy- 
drates are considered necessary with small horses," 
a conclusion which is entirely consistent with obser- 
vation and related facts. Lavalard 's . formula would 
furnish a 1,000- pound horse, doing ordinary work, 
with 12.1 lbs. of digestible nutrients daily, a quantity 
not inconsistent with the German standard. 

It seems to the writer that the results of the mas- 
terly and extensive metabolism investigations which 
Zuntz has carried on with a horse under various con- 
ditions may properly be cited in this connection. This 
investigator determined the oxygen consumption, which 
is equivalent to ascertaining the food use, by a horse 
at rest, when walking on a smooth level without load, 
and when performing both light and heavy work. 
First of all, it appears from his observations that 31.6 
per cent, or about one -third, of the total food energy 
can be converted into useful work. This is much less 



Food Needs of a Working Horse 373 

than the coefficient of useful work found by Wolff, 
whose conclusions Zuntz regards as erroneous. But 
even if Zuntz's figures are none too low, it is evident 
that the animal machine uses fuel with much greater 
economy than a steam engine where the coefficient of 
usefulness might not be over 10 per cent. The figures 
he reached show further that the total expenditure of 
energy by a horse weighing 1,000 pounds in walking 
one mile equaled 453 foot tons, which would be fur- 
nished by .164 lb. of digestible food. As 44.4 per 
cent of this, or 201 foot tons, was due to the effort 
of walking over and above the needs for maintenance, 
the extra digestible food needed per mile of walking 
was .07216 lb. 

Zuntz also found that when a horse increases the 
external mechanical labor performed such increase costs 
.001155 lb. digestible dry matter for each foot ton of 
work. On this basis the 264 foot tons of energy 
which is needed for pulling one mile a load with a 
draft of 100 lbs. would be furnished by .3049 lb. of 
food matter. The total food expenditure, therefore, 
for walking and a draft of 100 lbs. over a smooth, 
level road for one mile, would be .377 lb. digestible 
nutrients, and for twenty miles 7.54 lbs. If we add 
to this the 6.4 lbs. needed for mere maintenance, we 
have 13.94 lbs. digestible matter as the proper ration for 
a horse doing the work stated for a distance of 20 miles. 
These figures are certainly not inconsistent with the 
standard reached by other methods for a horse doing 
average work. Such a calculation is at least useful 
in showing the direct relation of food expenditure to 



374 The Feeding of Animals 

work performed, and the necessity of feeding a labor- 
ing animal somewhat proportionately to what he does. 
It should be borne in mind constantly that when the 
intensity of effort of the horse increases, even if only 
the same work is performed in a shorter time, the food 
needs per unit of work are greater. If a driver in 
making the regular number of trips to the railroad 
station needlessly hurries his horse, or if a drayman 
whips his team into a fast walk and then lets it stand 
idle, more food must be consumed than if the slowest 
possible gait was allowed. 

Source of the ration for working horses. — In treating 
of this matter we must, in the first place, consider the 
digestive apparatus or storage capacity of the "horse. 
It is certainly not adapted to the consumption of large 
quantities of coarse food, as is the case with ruminants. 
If a horse at severe labor needed 17.7 lbs. of digesti- 
ble dry matter per day, he could get it from hay only 
by eating over 40 lbs. — a most absurd requirement. It 
is especially necessary, therefore, with hard-working 
animals, that the larger part of their nutriment come 
from the concentrated feeding stuffs. Ten to 12 lbs. 
of hay is all a draft horse should consume in one day. 
Working horses on the farm generally eat too much 
coarse fodder. 

The net values of feeding stuffs are also important 
in this connection. It has been shown that the net 
energy value of a unit of digestible matter from dry 
hay is less than with that from the grains, and conse- 
quently when it is necessary to supply an animal with 
a large amount of energy for external mechanical uses, 



Proportion Nutrients in Work -Horse Ration 375 

requiring high feeding, we must resort to the grains 
in order to construct a ration of maximum efficiency. 

Concerning the nutritive ratio or proportion of pro- 
tein, in a ration designed for working horses, there is 
a variety of recommendations. The German standards 
call for ratios from 1:7 to 1:6, according to the severity 
of labor, the daily weight of protein for a 1,000-pound 
horse to be from 1.5 to 2.5 lbs. This is greatly more 
protein than is recommended by Lavalard, who v on the 
basis of extensive experience, declares that 1.15 lbs. 
of protein daily is sufficient for ordinary work, this to 
be increased to 1.35 lbs. when the labor becomes more 
severe. There is one fundamental fact that is pertinent 
to a discussion of this point, which is that the non- 
nitrogenous constituents of the ration are largely the 
source of muscular power. As stated before, it was 
formerly thought that muscular effort was sustained at 
the expense of muscular tissue, but when it was found 
that no more urea was excreted by men climbing a 
mountain than when they were much less active, this 
view was abandoned. Later researches have clearly 
shown that when work increases the excretion of car- 
bon dioxid increases in like proportion, without any 
important rise in the protein exchange. In other words, 
the carbohydrates and fats are largely the fuel that 
supplies energy for mechanical purposes. Common 
experience ratines this conclusion of science. How 
many horses and oxen have successfully endured severe 
labor on meadow hay, oats and corn, sometimes the 
grain being largely the latter! 

It is the judgment of the writer that a ration prop- 



376 The Feeding of Animals 

erly compounded from ordinary farm products, such 
as silage, roots, meadow hay, legume hays and the 
cereal grains, will generally contain protein in suffi- 
cient proportion, and will seldom need reinforcing with 
the nitrogenous feeding stuffs. It is probably true, how- 
ever, that when working animals are called upon to en- 
dure a severe strain material advantage is gained from 
introducing into the ration a small quantity of some 
nitrogenous feeding stuff, such as beans or oil meal. 

One of the opinions regarding the feeding of horses 
which has widely prevailed and which is still held by 
many is that oats in liberal proportions are essential 
to the successful maintenance of road and work horses, 
especially the former. It has been believed, as has 
been stated, that this grain imparts to the horse greater 
nervous activity or life than any other feeding stuff, 
and when it was announced that "avenine," an alkaloid, 
had been extracted from oats, this was quickly accepted 
as an explanation of their peculiar effect. We have 
given up the avenine and seem likely to modify our 
views in other ways, for it is becoming increasingly 
evident that other grains may be substituted for oats 
with no detriment to the horse and with a material 
saving to his owner. Barley, brewer's grains, maize, 
maize cake, wheat, wheat bran, wheat middlings, have 
been extensively and safely fed in the place of oats, 
wholly or in part, by experiment stations and in prac- 
tice by omnibus and horse -car companies. In this way 
the cost of maintaining horse labor is materially de- 
creased, for usually oats are comparatively much more 
expensive than other grains and the by-products in pro- 



Rations for Work -Horses 



377 



portion to their feeding value. Unless prices change, 
a farmer can generally afford to sell a part of the oats 
he raises and buy other grains, and he can do this 
with confidence that he will be able to maintain his 
road and working horses in proper flesh, and good 
health and spirit, on the cheaper materials. 

As a suggestion to feeders concerning the ways in 
which several feeding stuffs may be combined so as to 
furnish -practically the same quantity of digestible or- 
ganic matter, the following rations are presented as 
meeting the needs of a horse weighing 1,000 lbs. and 
doinff moderate work: 



10 lbs. timothy or mixed hay. 
llX lbs. oats. 

10 lbs. hay. 

10% ^s. oats and corn, equal 
parts by weight. 

10 lbs. hay. 

lO/o lbs. oats and barley, 
equal parts by weight. 

10 lbs. hay. 
8 lbs. oats. 
4 lbs. brewer's grains. 



f 10 lbs. hay. 

■i 5 lbs. corn. 

(_ 4% lbs. barley. 

C 10 lbs. hay. 

< 5 lbs. corn. 

(_ 6)4 lbs. wheat bran. 

C 10 lbs. hay. 

s 5 lbs. corn. 

(_ 6 lbs. brewer's grains. 

10 lbs. hay. 
4% lbs. barley. 
4 lbs. wheat bran. 
3 lbs. brewer's grains. 



10 lbs. hay. 
8 lbs. oats. 
4 lbs. wheat bran. 



10 lbs. hay. 
3% lbs. corn. 
4 lbs. wheat bran. 
4 lbs. brewer's grains. 

Silage, roots and other green materials may often 
be substituted for a minor part of the hay with advan- 
tage to the animal's appetite and health. 



378 The Feeding of Animals 

No definite rations are suggested for more severe 
labor. The amount of food must simply be increased 
with the amount of work performed. Any increase 
should apply to the grain and not to the hay, the pro- 
portions of the several feeding stuffs in the grain 
ration to remain the same in the larger quantity. It 
is well understood, of course, that a ration should 
increase proportionately faster than the amount of 
work done, and that an old animal generally demands 
higher feeding than does a young one. The condition 
of the road, the intensity of the effort and other cir- 
cumstances also modify the needs of the working horse, 
so that the feeder is always called upon to exercise 
the trained judgment which comes from experience. 
No working animal can be fed successfully by mechan- 
ical rules. 



CHAPTER XXV 

THE FEEDING OF POULTRY 
By William P. Wheeler 

One pronounced characteristic of birds is an in- 
tense vitality. Their life is never sluggish. The 
growth of the young and the transformation of food 
into eggs are exceedingly rapid. The temperature is 
high, running with different species from a little above 
100° F. to 112° or more. The energy expended in this 
direction is proportionately great, and material for its 
supply is in urgent demand; for a vigorous animal is 
the seat of rapid metabolic change. The large appe- 
tite is an indication of the extensive needs. The very 
active digestive apparatus must be in good order and 
supplied with efficient food. 

The domestic fowls may be classed with the ma- 
jority of birds as omnivorous. While seed-eaters like 
the common fowl are able to subsist for long periods 
on grain alone, as can also the goose by grazing, the 
natural food of most young birds is largely animal. 
Many wild birds which feed almost entirely on seeds 
supply their rapidly -growing young with an abundance 
of animal food. 

Kinds of foods. — It is a common experience that 
better success follows the use of several foods com- 

(379) 



380 The Feeding of Animals 

bined rather than a few, and it seems to be a fact 
that some variety is essential. While in practice a 
combination must be employed for best results which 
are partly due to the usually greater palatability and 
other indirect effects on the general health, it is not 
because of a greater nutritive value of the constitu- 
ents from different sources that the different foods are 
needed. The important consideration seems to be the 
proportion of constituents. In experiments made at 
the New York Agricultural Experiment Station, the 
better results from rations containing animal food 
were found to be largely due to the greater amount of 
mineral matter, chiefly phosphate of lime, in the ani- 
mal food used. When rations of grains naturally 
lacking in ash content were supplemented by bone ash, 
their efficiency was increased without addition of other 
food. For chicks during the periods of most rapid 
growth the rations of vegetable origin supplemented 
by material rich in phosphate of lime were equal or 
even superior to rations supplying large quantities of 
animal protein and fat. For laying hens the time 
during which such rations were equally efficient was 
limited to a few months. Rations containing animal 
food were much superior for ducklings, although the 
addition of bone ash to rations of grain and other 
vegetable food notably increased their efficiency. 

Although it is possible, for some purposes, to com- 
pound effective rations from grain alone when the 
deficiency of ash is made good, it is better in practice 
to use some animal food. A variety of grain food 
supplying enough nitrogenous matter is not always to 



Succulent and Bulky Foods 381 

be found, and animal foods, when rich in protein as 
most of them are, prove of great service; for with 
them can be freely fed some of the cheaper, starchy 
foods, typical among which is the palatable and re- 
markably efficient Indian corn. For fattening mature 
fowls animal food is not so important except when its 
use improves the palatability of the ration. This last 
is a matter always to be considered. 

Succulent vegetable foods are eagerly eaten by do- 
mestic fowls. Aside from the beneficial effect on the 
health of the birds, it is important to use such foods 
so far as possible, for the nutriment they supply is 
cheaply obtained. With most rations the more nitrog- 
enous fodders, such as clover, alfalfa, and very imma- 
ture grasses, are best. These foods also contain more 
of the needed lime than do grains. It must be re- 
membered, however, that fowls are not fitted to de- 
pend largely on such bulky materials while production 
is rapid. The goose is better adapted than most birds 
to live by grazing, but the liberal use of the more 
concentrated grain and animal foods has been found 
necessary except during the idle season. 

At the time of greatest egg production the choice 
of bulky foods should preferably be confined to those 
of the most tender and succulent nature. Certain ex- 
periments also indicate that a ration which contains 
any considerable proportion of dry or woody coarse 
fodder, although finely ground, is not suited to young 
chicks, and that only the more succulent kinds of 
bulky foods, like the first shoots of grasses and clovers, 
should be fed in the fresh condition. After the birds 



382 The Feeding of Animals 

approach maturity and growth is slower, so that a 
much larger proportion of the food is used for main- 
tenance, and during colder weather, when the heat 
from the extra energy required for digestion is useful, 
more of the coarse foods can be fed without apparent 
disadvantage. 

Incidental effects of the food. — Another reason, some- 
times a very important one, for using such foods as 
young clover, fresh or dried, is the effect on the color 
of the egg -yolk. Eggs from hens which are fed only 
certain grain and animal substances generally have 
yolks of a pale yellow color. This is often objected 
to by those who have a preference for eggs with darker 
orange -colored yolks. The liberal feeding of fresh or 
dried young clover, alfalfa or grass will generally in- 
sure the deeper coloration. The cause for this frequent 
lack of what may be considered the normal yellow 
color of the egg -yolk is not well known, but the 
occurrence of the pale color can be generally prevented 
by attention to the food. 

At the New York Experiment Station pens of hens 
which were fed alike except that no hay or green 
food was given to one while three others had different 
amounts, apportioned by geometrical ratio, of clover 
hay alternated with green alfalfa, produced eggs show- 
ing marked differences in color. The orange yellow 
shade of the yolk corresponded directly in intensity with 
the proportion of hay or green fodder in the ration. 
The greenish color of the white also varied, but not so 
regularly. Eggs from each lot were very uniform in 
appearance. 



The Organs of Digestion 383 

The differences in flavor and other qualities which 
are probably caused by the food cannot be satisfac- 
torily explained at present. They are, however, slight 
with normal rations. In general the color of the shell 
is determined by the breeding or by the individual 
characteristics of the fowl. 

Digestive apparatus. — The process of digestion with 
birds is essentially similar to that with mammals, 
although there are important differences in the ap- 
paratus hy which it is accomplished. It is necessary 
to know something of the general arrangement and 
working of the digestive canal when attempting to 
establish proper methods of feeding, and for a better 
selection and combination of suitable foods. 

Although some extinct species of birds were well 
supplied with teeth, existing forms have the mouth 
armed only with a horny beak. The common fowls 
must swallow grains whole, but are able to tear some 
food into small fragments, which they particularly do 
when feeding the young. Ducks, and geese more espe- 
cially, have the mouth supplied with laminae, which 
serve to cut soft herbage. 

In birds the salivary glands are small and the lim- 
ited amount of saliva probably has little effect on the 
food. 

The oesophagus is of great caliber and very expan- 
sible. It is dilated in the cervical portion in ducks 
and geese. In gallinaceous birds, instead of this dila- 
tation there is attached to, and forming practically a 
part of, the oesophagus, the reservoir called the crop. 
The food is temporarily retained in the crop, but is 



384 The Feeding of Animals 

changed very little other than being softened by the 
water swallowed with it, the small amount of mucus 
and the inconsequential amount of saliva. The high 
temperature doubtless assists this softening effect, and 
fermentation also progresses rapidly when food is re- 
tained long in the crop from injury or by overloading 
with coarse material. 

The divided crop of pigeons secretes, with both 
sexes, for several days after the young are hatched, 
a thick milky fluid which serves to feed the young 
birds. With other domestic birds the crop serves for 
little more than a temporary retaining reservoir. 

The stomach, which is a single organ in some birds, 
is represented by two reservoirs in domestic fowls. 
The first, through which the food passes after leaving 
the crop, is the glandular stomach, the succentric ven- 
tricle or proventriculus, and the second, closely con- 
nected, is the gizzard or muscular stomach. The first, 
from its structure, has been considered the true stom- 
ach, but it is now believed that gastric juice is secreted 
in the gizzard. The food does not accumulate in the 
first stomach, but in passing through carries along such 
juices as are there secreted. 

The gizzard is a powerful grinding apparatus. 
There is a strong lining which is capable of resisting 
great pressure and the action of the sharp sand and 
pebbles. In this organ the grains and seeds/ with 
other materials, are more finely ground than by the 
mastication of many other animals. 

The intestines are long in domestic fowls. While 
serving the same purpose as in mammals and having 




1 TONGUE 

X Esophagus , first portion 

3 Crop 

4 Esophagus , second portion 

5 Succentric Ventricle 

6 Gizzard 

7 Origin of duodenum 

8 Second branch of duodenal flexure 

9 ORigu or flo/tiNq portion op small ixTtsii** 

10.10 Small intestine 

11.11 CitCA 

12 Insertion of ecu 

13 TRegtum 

14 Cloaca 
15 -IS Pancreas 

16 Liver 

17 C.AIL- BLADDER 

18 SnrFN 



Fig. 10. Digestive apparatus of common fowl. 



386 The Feeding of Animals 

a general resemblance to the mammalian form, they do 
not clearly show the same divisions. The diameter is 
about the same throughout. The caeca, each of which 
is closed at one end and opens into the intestines at 
the other, seem to be important and essential modifi- 
cations of that canal. Each caecum is from six to 
seven inches long in mature fowls. Not far from the 
openings of the caeca the intestine ends in a dilatation, 
the cloaca, into which the genito- urinary passages also 
open. It is because of the mixing here of the undi- 
gested residues of the food with the secretions from 
the kidneys and with some other products of metabolism, 
that an accurate estimation of the digestibility of food 
by birds is so difficult. No satisfactorily accurate 
methods for separating some of the nitrogenous resi- 
dues from different organs seem yet to be perfected. 

Into the intestine shortly after it leaves the gizzard 
two ducts from the liver and two from the pancreas 
enter, discharging the bile and pancreatic juices. The 
liver, as usual, is a large organ. The pancreas also is 
very largely developed, and extends for several inches 
along the duodenal loop of the intestines, reaching in 
the common fowl a length of over five inches. 

Altogether the structure of the digestive apparatus 
of birds indicates extreme efficiency and the capacity 
for rapid work. A studj^ of it suggests, also, as does 
that of any complicated and delicately adjusted appa- 
ratus, that it should not be overloaded nor violently 
disturbed when running at high pressure. It may be 
said to run at high pressure while the extremely rapid 
growth of young birds occurs, and during the extended 



Constructive Material Required for the Body 387 

laying season, for the resulting products call for an 
uninterrupted supply of food and the transformation 
of all material that is available. Chickens of two 
pounds weight at ten weeks of age show a gain over 
the weight of the first week of nearly 1,700 per cent. 
Ducklings five pounds in weight at nine weeks show a 
gain during about eight weeks of 3,900 per cent. Such 
rates of growth are not very unusual for young fowls 
under favorable conditions. 

CONSTITUENTS OF THE BODY 

Whether the production of meat or of eggs is the 
prime object, the young fowl must first be grown. 
It is desirable, then, to consider what constituents make 
up the body of the animal, for all must be derived 
from the food. Many slight variations in composition 
exist, of course, but there is always a certain approxi- 
mation to the normal full-grown animal. 

In the whole body of the common fowl, unless espe- 
cially fattened, not far from one -half of the dry matter 
is protein and about 8 per cent ash. This of itself 
would suggest that a slow growth must follow the use 
of foods containing small amounts of nitrogenous and 
mineral matter. 

Analyses made, mostly by Jenter, at the New York 
Experiment Station, give as the average composition 
of the body of a Leghorn hen, typical of the laying 
breeds, 55.8 per cent of water, 21.6 per cent of protein, 
3.8 per cent of ash, and 17 per cent of fat. This is 
not the composition of the edible portion alone nor of 



388 The Feeding of Animals 

the carcass as found in the market, but that of the 
whole body, bones, blood, feathers, and all the viscera. 
The different parts of the body were all separately 
analyzed. Separate analyses of four individual hens 
each gave a close approximation to the average. The 
composition of the body of a Leghorn pullet in full 
laying was little different from the average for the 
hens, being 55.4 per cent of water, 21.2 per cent of 
protein, 3.4 per cent of ash, and 18 per cent of fat. 

The body of a mature capon (Plymouth Rock) con- 
tained 41.6 per cent of water, 19.4 per cent of protein, 
3.7 per cent of ash, and 33.9 per cent of fat. If the 
extra amount of fat were removed the composition would 
be very similar to that of the other fowls. In younger 
and immature birds the percentage of fat is very much 
less than in older birds. 

The egg, which, aside from the shell, is potentially 
a chick, shows in the general proportions of the con- 
stituents a striking resemblance to the body of the 
grown bird. Of the dry matter of eggs analyzed, 
aside from the shell, 49.8 per cent on the average was 
protein, 3.5 per cent ash, and 38.6 per cent fat. Of 
the dry matter of the bodies of hens 48.9 per cent was 
protein, 8.6 per cent ash, and 38.5 per cent fat. 

Of the total dry matter in the entire egg 35.6 per 
cent is ash, 25.9 per cent fat, and about 33.3 per cent 
protein, or 38.5 per cent if estimated by difference. 
The fresh egg with a good firm shell consists of about 
11.4 per cent shell, 65.7 per cent of water, 8.9 per 
cent of fat, 11.4 per cent of protein by factor, or 13.2 
per cent by difference, and .8 per cent of ash* con- 



The Importance of Water 389 

stituents aside from the shell. Of this ash 53.7 per 
cent is phosphoric acid. Over .2 per cent of the edible 
portion of the egg is phosphorus. This composition is 
the average from twenty-four analyses by Thompson, 
and eighteen by Wheeler, representing over 400 eggs 
from hens of several breeds under different rations. 
None of the analyses differed much from the average. 

Necessity for considering the water. — In the products 
which have been mentioned, as in most animal products 
sought by feeding, there is always a large amount of 
water. In every dozen eggs there is a pint of water. 
Aside from that necessary for constructive use there is 
required for the activities of the living animal a free 
supply. Particular mention is made of the necessity 
for water, because its great importance is sometimes 
overlooked, for an especially provided supply is not 
necessary under some circumstances. Instances occur 
when the lack of water is the cause of ill success. 

The organic and mineral nutrients in food. — Men- 
tion of the characteristics and composition of the 
different nutrients of the food and a discussion of 
their functions will be found elsewhere in this volume. 
The facts apply to the feeding of poultry as well as 
to that of other animals. 

It appears from present knowledge that protein 
derived from animal sources is more efficient for cer- 
tain uses, particularly the feeding of ducklings, than 
that derived from vegetable foods. Previous mention 
has been made of experiments at the New York Ex- 
periment Station, the results of which accord with 
this assumption. The rations which contained animal 



390 The Feeding of Animals 

food proved much more efficient than those of vege- 
table origin, the latter having, according to the ordi- 
nary methods of estimation, the same nutritive value 
as the former. 

It seems probable that the ash constituents have 
sometimes not been sufficiently considered in feeding. 
While the importance of the mineral nutrients can be 
largely overlooked without serious practical disadvan- 
tage when feeding some animals for certain purposes, 
it must be given consideration when feeding domestic 
fowls. While in milk, for instance, about 5 per cent 
of the dry matter is ash, in eggs over 35 per cent 
of the dry matter is represented by the mineral con- 
stituents. 

The shell of the egg, which represents about 11 
per cent of the fresh egg, consists almost entirely of 
carbonate of lime. Most grain foods which naturally 
constitute the bulk of ordinary rations contain little 
mineral matter and the amount of lime is notably 
low. For simply supplying the deficiency of material 
for the egg shell, carbonate of lime in the form of 
oyster shell can be used. This was shown in experi- 
ments at the New York Experiment Station made 
with laying hens after they were closely confined on 
a clean floor for over three weeks. It was then found 
that about nine -tenths of the lime in the egg shell 
was unaccounted for in the food aside from the oyster 
shells which were fed. 

While less than 10 per cent of the body of a 
fowl is mineral matter, it consists largely of phosphate 
of lime and exceeds in proportion that of many foods. 



Salt and Grinding Material 391 

The bony framework is also rapidly formed in the 
growing bird, so that mineral matter is in imperative 
demand. The results of many trials made at the New 
York Experiment Station are clearly in accord with 
this assumed need. As has been previously men- 
tioned, the addition of phosphate of lime from several 
sources to rations for young fowls has noticeably 
increased their efficiency. 

Common salt in considerable quantity is a neces- 
sity to the living animal. Some foods contain a 
probably sufficient amount, but in others the propor- 
tion is very small. In order to make sure of an 
excess and to avoid any possible deficiency it is well 
to add salt regularl}- to the food, especially when it 
also increases the palatability of the ration. About 
five ounces in every 100 lbs. of food has been found 
a safe proportion. Fowls regularly accustomed to salt 
are not likely to eat an injurious quantity of very 
salty material when it is accidentally within their 
reach. Pigeons are very fond of salt and a liberal 
allowance is generally considered necessary to insure 
health in the loft. 

Fowls at liberty are generally able to find grit 
enough in the form of sharp pebbles and sand to facili- 
tate the grinding which occurs in the gizzard. When 
they are confined or do not have extended range, 
sharp and hard grit of some kind should always be 
freely supplied. Clean, sharp sand is useful for the 
very young birds, and is quite generally considered an 
essential part of all mixtures fed to ducklings. Good 
results accompany its free use. 



392 The Feeding of Animals 

THE STUDY OF RATIONS AND DEDUCTION OF STANDARDS 

In studying and comparing: different rations, it is not 
possible to consider all the combinations that can be 
made of the many foods. It is only practicable to con- 
sider foods with reference to their varying proportions 
of constituents. The only portion of these constitu- 
ents of nutritive value is that which can be digested. 
Therefore, in compounding rations, we are guided pri- 
marily by the amount of the digestible nutrients supplied 
by the food; and feeding standards are for convenience 
limited to a statement of the assumed requirements in 
terms of digestible protein, ash, carbohydrates and fat. 
The bulk of the ration supplying these nutrients must 
also, of course, fall within certain limits. In the ab- 
sence of enough specific data calculations must be based 
on the coefficients of digestibility observed for other 
animals. These afford safe enough approximations for 
present use, for the feeding standards must be largely 
provisional. 

Growth and egg production can only be sustained 
by the food in excess of that required to support life, 
although egg production can temporarily occur at the 
partial expense of the body. The amount of food, 
then, required for simple maintenance puts a limit on 
one side to an efficient and profitable ration. In the 
other direction, it is only limited by the capabilities of 
the individual animal. So the highest possibilities 
depend altogether on the intelligent judgment, and 
careful, daily attention of the experienced feeder. In 
a general way only averages can be considered. 



Food Required for Maintenance 393 

Maintenance rations. — A number of feeding trials 
made at the New York Experiment Station supply in- 
formation relative to the amount of food required for 
simple maintenance. The amount varies, as might be 
expected, with the size of the animal. The larger fowls 
required more food, but much less for each pound of 
live weight. These feeding trials did not cover any 
molting period and egg production was, for the time, 
suspended. From the data secured maintenance ra- 
tions have been deduced which correspond very closely 
to those actually fed for quite extended periods during 
which practically no change in live weight occurred. 
The data were from an aggregate of fifty -two capons, 
averaging by different lots from 9 to 12 lbs. in weight, 
for 158 days' feeding, and from sixty hens ranging 
from 3 to 7 lbs. in weight for 150 days 7 feeding. 

The rations are stated in the following tabulated 

form : 

Maintenance Rations 

Digestible nutrients per day for each 100 pounds live weight 

Total dry Carbohy- Fuel Nutritive 

matter Ash Protein drates Fat value ratio 
lbs. lbs. lbs. lbs. lbs. Cal. 

Caponsof 9 to 12 lbs. wt...2.30 .06 .30 1.74 .20 4,600 1:7.5 

Hens of 5 to 7 lbs. weight.. 2.70 .10 .40 2.00 .20 5,300 1:6.2 

Hens of 3 to 5 lbs. weight.. 3.90 .15 .50 2.95 .30 7.680 1:7.4 

Rations for laying Iiphs. — Hens in full laying seem 
to require rations which have a larger relative content 
of protein and ash, and which show an increase in 
fuel value of from 15 to 40 per cent, according to size, 
over those required for maintenance. The following 
standards approximate the requirements : 



394 The Feeding of Animals 

Rations for Hens in Full Laying 

Digestible nutrients per day for each 100 pounds live weight 

Total dry Carbohy- Fuel Nutritive 

matter Ash Protein drates Fat value ratio 

lbs. lbs. lbs. lbs. lbs. Cal. 

Hens of 5 to 8 lbs. weight.. 3.30 .20 .65 2.25 .20 6,240 1:4.2 

Hens of 3 to 5 lbs. weight. .5.50 .30 1.00 3.75 .35 10,300 1:4.6 

These standards are not absolute and inflexible 
rules, for such would not be justified by a thousand 
times the number of available data. They supply a 
definite starting point, and are not supposed to obviate 
the use of judgment. Because it is found convenient, 
on account of different requirements and capabilities, 
to divide hens into two groups, it should not be pre- 
sumed that a hen just under five pounds in weight 
must always have one ration or a hen just over five 
pounds must always have the other. 

A ration which corresponds to the standard given 
for maintenance for hens of the larger size could be 
composed of one pound of cracked corn, one pound of 
corn meal, one -half pound each of ground oats, wheat 
middlings, and clover hay, one -fourth pound of fresh 
bone and two ounces of meat scraps. 

The following stated ration is given as an illustra- 
tion of one which would supply the nutrients called for 
in the standard for laying hens of the larger size: One 
pound of cracked corn, three -fourths pound of wheat, 
three-fourths pound of corn meal, one -half pound each 
of wheat middlings, buckwheat middlings, and animal 
meal, two -thirds of a pound of fresh bone, and three - 
fourths of a pound of young green alfalfa. 

Rations for young birds. — The requirements of the 



Standard Rations for Young Fowls 395 

rapidly -growing young fowl are so constantly chang- 
ing that a satisfactory average ration for any extended 
period cannot be easily formulated. In the following 
statement of rations for chicks they are averaged for 
periods of two weeks at different ages during the time 
of most rapid growth. The ration for the last period 
will suffice for several weeks longer, although the 
amount required per 100 pounds live weight will grad- 
ually diminish up to maturity. For fattening nearly 
mature fowls a ration with a wider nutritive ratio of 
about 1:8 can be liberally fed for limited periods. 

The duck grows faster than the common fowl, and 
more food is required during an equal time. Rations for 
ducklings differing somewhat from those for chicks are 
given separately. 

Rations for Chicks 

Digestible nutrients per day for each 100 pounds live weight 



For the first 2 weeks 

From 2 to 4 weeks of age. . 
From 4 to 6 weeks of age. . 
From 6 to 8 weeks of age. . 
From 8 to 10 weeks of age. 
From 10 to 12 weeks of age 



Total dry 
matter 


Ash 


Pro- 
tein 


Carbohy- 
drates 


Fat 


Fuel 
value 


Nutritive 
ratio 


lbs. 


lbs. 


lbs. 


lbs. 


lbs. 


Cal. 




10.1 


.5 


2.0 


7.2 


.4 


18,800 


1:4.1 


9.6 


.7 


2.2 


6.2 


.5 


17.730 


1:3.4 


8.6 


.6 


2.0 


" 5.6 


.4 


15.640 


1:3.3 


7.4 


.5 


1.6 


4.9 


.4 


13,780 


1:3.7 


6.4 


.5 


1.2 


4.4 


.3 


11,680 


1:4.3 


5.4 


.4 


1.0 


3.7 


.3 


10.000 


1:4.4 



Rations for Ducklings 
Digestible nutrients per day for each 100 pounds live weight 





Total dry 




Pro- 


Carbohy 




Fuel 


Nutritive 




matter 


Ash 


tein 


drates 


Fat 


value 


ratio 




lbs. 


lbs. 


lbs. 


lbs. 


lbs. 


Cal. 






17 2 


1.6 


4.0 


11.2 


1.4 


34,180 


1:3.7 


From 2 to 4 weeks of age. . 


. 17.0 


1.5 


4.1 


10.1 


1.3 


31,900 


1:3.2 


From 4 to 6 weeks of age. . 


. 11.2 


.8 


2.7 


7.0 


.7 


21,000 


1:3.3 


From 6 to 8 weeks of age. . 


8.0 


.6 


1.7 


5.2 


.5 


14,940 


1:3.8 


From 8 to 10 weeks of age. 


7.0 


.5 


1.4 


4.7 


.4 


13,030 


1:4.1 


From 10 to 15 weeks of age 


4.6 


.3 


.9 


3.2 


.2 


8,470 


1:4.1 



396 The Feeding of Animals 

As an example of a day's ration which would cor- 
respond to the requirements of the standard given for 
young chicks during the second week the following is 
stated: Four pounds of cracked wheat, two pounds of 
granulated oat meal, three pounds of corn meal, one- 
half pound each of wheat middlings, buckwheat mid- 
dlings, ground oats and old process linseed meal, two 
and one -fourth pounds of animal meal and two and 
three -fourths pounds of young green alfalfa. This 
would feed from eight hundred to a thousand chicks 
of this age. 

Another ration in accord with the standard given 
for ducklings about three weeks old might be constituted 
as follows: Eight pounds corn meal, three pounds wheat 
middlings, two pounds ground barley, two pounds of 
old process linseed meal, six pounds of animal meal, 
two pounds of fresh bone and three pounds of young 
green alfalfa. This and other specimen rations are 
given under the assumption that free supplies of sharp 
grit, as well as water, are also provided. 

A consideration of the adaptability of the different 
foods, aside from their composition, and of the appar- 
ent requirements of the young at different periods sug- 
gests a ration somewhat wider in nutritive ratio for 
the first few days than for some weeks afterward. . 

In providing a ration, it may be possible to devise 
one in accord with the formal standard which will be 
decidedly inefficient at times if the chemical composition 
and coefficients of digestibility are alone considered. 
The adaptability of foods that are palatable must be 
considered. The difference in the energy required to 



The Adaptability of Certain Foods 397 

digest various foods which can supply equal proportions 
of digestible matter may be also at certain times an 
important factor. 

A large number of. the ordinary grains seem prac- 
tically interchangeable and many grain by-products can 
be freely substituted for different whole grains or for 
each other and all combined as desired. But some 
foods, such as cottonseed meal, do not seem suited to 
common fowls, even in very small quantities. Linseed 
meal can be fed more freely, but the un ground flax- 
seed is less satisfactory. It is probable that oats, 
whole or ground, which appear so valuable sometimes, 
should not be freely used at other times. About thirty 
per cent of the entire grain is hull. To obtain the 
available material from this requires an expenditure 
of energy that can be better applied during periods of 
rapid transformation, especially during the first few 
weeks of the young bird's growth. The products of 
the oat kernel, however, from which the hull has been 
separated are in the unquestioned class of foods. The 
same observation applies to buckwheat, some kinds of 
pea meal and to certain other foods less commonly 
used, containing a large proportion of crude fiber. 
Reference to this point has been made before under 
the topic of coarse and bulky foods. 

Primary consideration has naturally been given to 
those domestic fowls upon which we depend for the 
great bulk of eggs and meat. Other kinds are of 
considerable importance in certain localities, or often 
to the fancier, but concerning them not enough is 
recorded to establish separate feeding standards. It 



398 The Feeding of Animals 

is probable that their requirements will be found to 
correspond fairly well with those of either the duck 
or of the common fowl. The general food of the tur- 
key is similar to that of the common fowl, but it should 
be less artificial, and conditions of general feeding 
more nearly resembling those which exist in a wild 
state are required. 

Unsatisfactory as is our present knowledge of the 
fundamental laws which underlie the science of nutri- 
tion applied to man and other animals, there are 
nevertheless volumes of carefully collected data that 
make it possible to ascribe fairly narrow limits to 
their operations. Compared with mammals, however, 
the class of birds has received very little considera- 
tion. There have been a few careful studies made, 
but for lack of enough information our feeding must 
be guided by the rules applying in common to all 
animals. Undoubtedly the accepted laws of nutrition 
observed for other animals are applicable in a general 
way to domestic fowls, and it is safe to apply in the 
light of the specific data we have any general prin- 
ciples of feeding that have already been established. 
This has been done in formulating the feeding stand- 
ards which are here presented, and all available data 
of a reliable character have been considered. There 
have not been enough, however, to justify narrow 
limitations, and the suggested standards should not 
be considered final and unchangeable. They simply 
represent the averages of rations which under careful 
management and like conditions have given better 
results than various other rations with which they 



Modifications of the Standard Important 399 

have been contrasted. Slight modifications were made 
in accord somewhat with the habits of the different 
fowls and with a consideration of the character of 
the products desired. It is important that the feeder, 
while following such standards in a general way, 
should give enough consideration to the subject to 
make modifications suited to the species and breed 
and to his particular conditions of market and farm. 



CHAPTER XXVI 

THE RELATION OF FOOD TO PRODUCTION 

One of the questions much discussed by farmers, 
and which has an important bearing upon the eco- 
nomics of animal husbandry, is the food cost of the 
various animal products. To illustrate, a herd of cows 
consumes a certain quantity of food and produces a 
certain weight of milk, milk solids, cheese or butter, 
according to the terms in which we state the produc- 
tion. If the same food is fed to a lot of steers a cer- 
tain increase in their live weight is secured. There is 
in each case a relation of quantity between the food 
and the product. The food cost, that is, the food con- 
sumption, involved in growing a pound of beef, is quite 
unlike the food requirements for producing a pound 
of pork, a pound of veal or a pound of eggs. If we 
consider merely food expenditure, that branch of ani- 
mal husbandry is most economical of raw materials in 
which the largest proportion of the food dry substance 
is converted into some new, useful product, or, differ- 
ently stated, where the food units bear the lowest ratio 
to a unit of product. 

In presenting the matter it is necessary to first de- 
fine our units. What shall we accept as a food unit? 
Certainly it cannot be a pound of food as eaten. One 

(400) 



Food Cost of Production 401 

farmer feeds his cows silage or roots, and grain, with 
but little hay, while another fattens steers on dry food 
alone. A comparison of production in the two in- 
stances on the basis of the gross weight of food con- 
sumed would be absurd, because with the cows the dry 
matter is largel}* diluted with water. It would be 
equally absurd to accept the dry matter in the ration 
as a standard. In instituting a comparison between 
bovines and swine we must remember that the former 
consume materials much less digestible than do the 
latter, and so a unit weight of food does not represent 
the same weight of available nutrients with the two 
classes of animals. 

We should, so far as possible, reduce rations to 
their units of nutritive value, and so the digestible 
dry matter is now the nearest approach we can make 
to a basis for comparing rations with each other or 
with the production which they sustain. It follows, 
then, that if we wish to show the comparative economy 
of production in dairy farming and in beef farming, 
food alone considered, we should express this relation 
on one side in terms of digestible dry food substance. 

What shall we consider as a unit of production ? 
We may answer this question from two standpoints. 
We may measure production by the quantity of the 
commercial article which the farmer places on the 
market, or by the actual contribution which any 
given production makes to the food resources of the 
human family. More specifically stated, we may deter- 
mine the relation of a unit of digestible food sub- 
stance to the live animal, beef, pork, milk, cheese, 



402 The Feeding of Animals 

butter or eggs resulting from its use, and calculate 
the ratio of any one of these to the actual nutrients 
consumed, or we may ascertain the ratio of food con- 
sumption to the edible dry substance in the various 
animal products. The latter is the important ratio to 
consider if we are seeking to learn how we can most 
efficiently apply farm crops to the sustenance of the 
human family. 

This study of food economics requires a knowledge 
of several factors. In the first place, we must have 
the information coming from feeding experiments, 
where a careful record has been kept of the kind and 
amount of food consumed and of the weight of the 
resulting growth, milk, eggs, or what not. This in- 
formation must be supplemented by a knowledge of 
the digestibility of feeding stuffs, of the ratio between 
the live animal or other gross product and the com- 
mercial products and of the composition and propor- 
tion of edible material supplied by the commercial 
article. For instance, we find it takes, on the average, 
7.40 lbs. of digestible organic substance in the ration 
to produce one pound of growth in a steer, and we 
have learned by slaughter tests that the average per 
cent of carcass for 97 animals was 61.4, and by the 
butchers' and chemists' analyses, that the carcass 
contains an average of 33.2 per cent of edible dry 
matter. From these data it is easy to calculate that 
12 lbs. of digestible food are needed for the growth 
of one pound of carcass or 36.3 lbs. for the growth 
of one pound of edible beef solids. 

The following tables give the data upon which is 



Productivity of Farm Animals 403 

based the productive power of food when utilized by 
the various classes of animals. Data of this kind are 
practically our only means of studying the economics 
of producing those human foods which are most costly 
in proportion to their nutritive value, a study which is 
very important wherever it becomes necessary to econo- 
mize energy. It shows the coefficients of efficiency of 
various species of animals in maintaining the human 
species. The sources of all these figures are not given, 
for they are so numerous as to make this difficult : 

Production by Farm Animals 

Proportions of carcass and edible substance 

Carcass Per cent* Per cent of 
Number in per cent of edible edible dry 

of of live dry matter matter in live 

animals weight in carcass animal 

Steers, general average 97 61.4 33.2 20.4 

Steers, Iowa 5 64. 33.2 21.2 

Steers, Kansas 5 61.4 33.2 20.4 

Steers, Mainet 8 57.7 32.3 18.6 

Sheep 4 50.7 37.4 19. 

Lambs 44 50.7 33.7 17.1 

Lambs, Iowa 133 54. 33.7 18.2 

Swine, general average 97 81.2 62.7 50.9 

Pigs, Iowa 56 77.9 62.7 48.8 

Calves 23 57.2 22.2 12.7 

Fowl, large 12 80.8 27. 21.8 

Fowl, small 7 78. 27. 21.1 

Chickens, broilers 107 82. lj 14.7 12.1. 

Eggs 34§ 88.8|| 26.3 23.3** 

* From Bull. 28, Office of Experiment Stations. Revised edition, 
t Grown from calfhood, entire bodies analyzed. 
tNot drawn. 
§ Number of samples. 
II Per cent after removing shells. 
**In eggs with shells. 



404 



The Feeding of Animals 



Relation of food to product 

Diges- Diges- Diges- 
tible org. tible org. tible org. 
substance substance substance 
Number produc- produc- producing 
of Number ing 1 lb. ing 1 lb. I lb. in- 
experi- of increase increase crease 
ments animals live wt. carcass edible sol. 
lbs. lbs. lbs. 

Milk, average 61 391 .72 5.55 

Milk, New York* 113t 30 .63 4.85 

Steers, average 32 242 7.40 12. 36.3 

Steers, la., growth 9 to 24 m. 1 5 5.97 9.33 28.1 

Steers, Kansas, 3 years old. 1 8 8.08 13.16 39.6 

Steers, Maine 1 4 6.65 11.5 35.7 

Sheep and lambs, average. . 11 122 7.20 14.2 37.9 

Lambs, Iowa, growth while 

fattening . . 2 133 5.63 10.43 30.9 

Swine,| average 277 1,385 3.29 4. 6.4 

Pigs, Iowa 1 56 3.03 3.89 6.2 

Calves, average 3 30 1.57§ 2.70 12.3 

Fowl, large, to 5 or 6 mos. || 6 5.10 6.30 23.4 

Fowl, small, to 5 or 6 mos. || 6 5.10 6.50 24.2 

Chickens, broilers, 12 wks. || 15 3.48** 4.20 28.8 

Eggs|| 14 139tt 4.56tt 5.10 19.6 

The figures of the foregoing tables can be regarded 
as being trustworthy for average conditions. They are 
obtained from the recorded data of experiment stations, 
and involve a large number of observations with dairy 
cows and with growing and fattening animals. 

In most cases the amount of digestible matter in 

* Extending over seven years. 

t Short periods. 

X Deduced from compilation by Dr. Armsby for U.'S. Dept. of Agriculture. 

8 Dry matter, mostly from milk, practically all digestible. 

II Unpublished data from experiments at the New York Agri. Expt. Station. 
**4.35 lbs. dry matter, assumed to be 80 per cent digestible, 
tt Egg product, 100 eggs per year. 
XXS 5.70 lbs dry matter, assumed to be 80 per cent digestible. 



Relative Food Cost of Animal Product* 405 

the ration is calculated from the average coefficients 
of digestibility. 

The facts brought out by this study of the relation 
of food to product are emphatic and suggestive. In 
order to display them as clearly as possible there are 
shown in the next table the quantities of the various 
commercial animal products, and of human food in 
animal forms, which can be produced by the use of a 
quantity of cattle food containing 100 lbs. of digesti- 
ble organic matter: 

Relation of food to product 

Produced by 100 lbs. digestible or- 
ganic matter in ration. 

Marketable Edible 

product solids , 

lbs. lbs. 

Milk, general average 139. 18. 

Milk, New York experiments 158.7 20.6 

Cheese, green 14.8 9.4 

Butter 6.4 5.44 

Steers, general average, live weight.. . 13.5 

Steers, Iowa, live weight 16.8 

Steers, Kansas, live weight 12.4 

Steers, Maine, live weight 15. 

Steers, general average, carcass 8.3 2.75 

Steers, Iowa, carcass 10.7 3.56 

Steers, Kansas, carcass 7.6 2.52 

Steers, Maine, carcass 8.7 2.84 

Sheep and lambs, general average, 

live weight 13.9 

Lambs, Iowa, live weight 17.8 

Sheep and lambs, general average, 

carcass 7. 2.60 

Lambs, Iowa, carcass 9.6 3.23 

Swine, general average, live weight. . . 30.4 

Swine, Iowa, live weight 33. 



406 The Feeding of Animals 

Relation of food to product— continued 

Produced by 100 lbs. digestible or- 
ganic mattei in ration. 

Marketable Edible 

product solids 

lbs. lbs. 

Swine, general average, carcass 25. 15.6 

Pigs, Iowa, carcass 25.7 16.1 

Calves, live weight 63. 7 

Calves, carcass 36.5 8.1 

Fowl, large, live weight 19.6 

Fowl, small, live weight 19.6 

Fowl, dressed carcass, average 15.6 4.2 

Broilers, live weight 28.7 

Broilers, dressed carcass 23.8 3.5 

Eggs 19.6 5.1 

It may properly be said of the foregoing figures 
that they are only averages and that the relation of 
food to production varies with different animals of the 
same class and with the conditions involved. While 
this is true, the relations shown in the preceding 
calculations represent differences too wide to be ex- 
plained on any other ground than that the various 
animal products have greatly unlike food cost. 

The most noticeable fact brought out by this com- 
parison is the low relative food cost of milk and other 
dairy products. The growth of a pound of edible 
beef solids requires a food expenditure nearly seven 
times as great as is necessary for the elaboration of 
a pound of milk solids. On the other hand, swine 
are fed with nearly as great economy as are milch 
cows. In fact, when proper allowance is made for 
the period of growth of the cow and for the annual 
periods when she is giving no milk, she seems to have 



Relative Food Cost of Animal Products 407 

no advantage over the pig except in kind of product. 
Next in the order of economical use of food conies 
the calf, when fed largely on milk. Poultry products 
stand next in line. Sheep and lambs do not differ 
materially from steers, meat products of these two 
classes requiring the largest proportional food con- 
sumption of any form of growth here considered. The 
order of food efficiency as related to the several animal 
products is therefore as follows : milk, pork, veal, 
poultry and eggs, mutton and beef. The common 
claims that the food cost of a pound of butter is no 
greater than that of a pound of dressed carcass is 
not borne out bj r these average figures. 

It is suggestive, at least, to notice that the food 
factor is inversely as the labor factor in these various 
lines of production. For instance, labor is a large 
factor of the cost of a pound of any dairy product, 
and a small factor in the cost of beef or mutton, while 
the reverse is emphatically true of the food cost. 



CHAPTER XXVII 

GENERAL MANAGEMENT 

There are many considerations pertaining to the 
feeding and management of live stock that have a 
more or less common application to all classes of 
animals and which may be discussed conveniently 
under one head. They are partly of a business char- 
acter and to quite an extent lie outside the chemical 
and physiological principles of nutrition. Some of 
those questions are matters of much importance, but 
many of them which relate, for instance, to times and 
methods of feeding are given a prominence in current 
discussions out of proportion to their real influence 
in determining success. It should be understood, too, 
that many of the details of practice are not limitable 
by 'fixed rules but must be variable according to the 
conditions involved. Tact and judgment are demanded 
of the farmer who wisely adjusts his practice to busi- 
ness principles. 

General management properly includes, among 
other considerations, the following topics: 

(1) The selection of animals; (2) manipulation of 
the ration and manner of feeding; (3) the intensity 
of feeding; (4) environment and treatment of the 
animal. 

(408) 



The Animal as a Business Factor 409 

SELECTION OF ANIMALS 

The object to be sought in feeding animals is the 
conversion of a unit of food into the largest possible 
quantity of the product best adapted to the producer's 
commercial opportunities, and here the limitations of 
the animal are often the limitation of the farmer's 
profits. Within each species varietal and individual 
differences determine the rate of production and also 
whether the food shall be transformed into poor milk 
or rich milk, inferior beef and mutton or superior 
meat products, fine wool or coarse, trotters or draft 
horses, and small eggs or large ones. 

The selection of animals should have reference to 
three general factors, which largely fix the rate and 
character of production, — viz., breed, individuality 
and age. 

The selection of cows. — The breed and individuality 
of the cow largely determine the quality of her product 
and the quantity of production from a unit of food. 
Neither heavy feeding nor skill in compounding rations 
can be made the means of causing her to overstep her 
constitutional limitations. 

The selection of cows simply with reference to breed 
is a question of adaptability. If the production of 
milk at the minimum food cost per unit of volume is 
the result most desired, the dairy breeds characterized 
by milk with a low proportion of solids should be 
chosen, but if the object is to merely secure butter -fat 
with the lowest possible food expenditure, the so-called 
butter breeds are in general to be preferred. 



410 The Feeding of Animals 

When the chief consideration is the manufacture 
of milk solids most economically, we must deal not so 
much with breeds as with individuals. In fact, with 
all breeds and with animals of no breed, individual 
capacity is the consideration fundamental to profitable 
feeding. Some Holsteins will return both more milk 
and more butter for a unit of food cost than will some 
Jerseys, and the reverse is equally true. There is no 
magic in heredity which overcomes lack of capacity 
either for the breeder or for the dairyman. 

The ''general -purpose" cow has been much dis- 
cussed in recent years. While her specifications have 
never been fully and clearly set forth, it is supposed 
that she is an animal reasonably profitable along both 
beef and milk lines. It is doubtful whether such a 
cow, even if she exists, is one adapted to general utility. 
There are few localities where milk is not more profit- 
able than beef or beef more profitable than milk, and 
whichever is the more profitable should be produced 
by an animal of specialized capacity. Any extra value 
which the calves' and the cow's carcass may have when 
flesh -forming tendencies are prominent, will generally 
come far short of compensating for a merely mediocre 
milk yield in those localities where there is a market 
for milk and its products; and the stockman who is 
endeavoring to put on the market beef animals of the 
highest quality cannot afford to compromise with dairy 
qualities. Milk formation and flesh formation are an- 
tagonistic, and not correlated, functions, both of which 
do not operate intensely in the same individual. At 
present we have no breed or fixed type of animals 



Animals for Meat Production 411 

that can be regarded as presenting and perpetuating 
"general -purpose" qualities. Such a type, if found at 
all, must be sought among individuals. 

The selection of animals for meat production. — It is 
generally conceded that the selection of breeds of the 
beef and mutton types is essential to the highest suc- 
cess in the production of meat. This is true with 
steers, not because those from the dairy breeds will 
make very much slower growth than Shorthorns or 
Herefords, for this does not seem to be the fact, but 
because the quality of the product is higher with the 
latter, that is, the proportion of valuable parts is 
greater and the distribution of fat and lean tissue is 
more desirable, in the distinctly beef animal. 

A choice from the beef and mutton types and from 
the various breeds of swine may safely be left to per- 
sonal preference. Many experiments have been con- 
ducted with a view of determining the relative capacity 
of growth of the prominent breeds of bo vines, sheep, 
and swine, and the testimony so far adduced is of a 
negative character and does not point to any one breed 
of any species as clearly superior to all others. It is 
well understood, however, that within every breed in- 
dividual variations are important and that from a 
"bunch" of steers it is possible to select some animals 
superior to the others in their capacity to make profit- 
able use of food. 

A most important factor in this connection is the 
relation of age to the profits of meat production. 
Nothing has been more fully established by experi- 
mental evidence than that the younger the animals 



412 



The Feeding of Animals 



the larger the ratio of increase to body weight and the 
greater the increase for each unit of food consumed. 

Some of the more striking evidence on these points 
is presented in the following figures: 

Results with steers from five breeds slaughtered at the Smithfield 
{England) Fat- Stock Show {from Henry'' s compilation) 

Age Number animals Daily gain 

One year old 77 2.00 lbs. 

Two years old 89 1.76 " 

Three years old 54 1 .58 ' ' 

Steers at American Fat- Stock Show {Stewart's compilation) 
Age Number animals Daily gain 

297 days 30 2.6 lbs. 

612 " 152 2.2 " 

943 " 145 1.7 " 

1,283 " 133 1.5 " 



American experiments with pigs 


{Henr 


y's 


compilation) 


Weigbt of pigs 


Number feeding trials 


Food for 100 lbs. gain l 


38 


lbs. 


41 






293 lbs. 


78 


< < 


100 






400 " 


128 


< i 


119 






437 " 


174 


(< 


107 






482 " 


227 


1 1 


72 






498 " 


271 


< < 


46 






511 " 


320 


< i 


19 






535 " 



Results of Danish experiments with pigs 
Weight of pigs Number experiments Food for 100 lbs. gain 

35 to 75 lbs. 
75 to 115 " 

115 to 135 " 

155 to 195 " 

195 to 235 " 

235 to 275 " 

275 to 315 " 



3 


376 lbs 


10 


435 " 


13 


466 " 


15 


513 " 


14 


540 " 


11 


614 " 


3 


639 " 



Treatment of Ration 413 

Testimony of this character is abundant, and the 
lesson for practice is that animals should be fed for 
market at the earliest age that is consistent with other 
conditions. 

MANIPULATION OF THE RATION 

A great deal of experiment and discussion has been 
devoted to the economy of various methods of treating 
cattle foods, such as cutting, grinding, wetting and 
cooking. The economy of these operations requires no 
extended comment. It is a simple and safe rule that 
any fodder or grain that in its natural condition is 
palatable, is wholly eaten and is thoroughly masticated, 
should be fed without the unnecessary expense which 
these manipulations would cause. Grinding any mate- 
rial that is not otherwise thoroughly masticated doubt- 
less increases the efficiency of the food, but when the 
grinding costs as much as 10 per cent of the market 
price of the grain it is doubtful if any advantage 
accrues. Cutting, unless for the purpose of mixing, 
has the sole advantage of saving the animal a little 
work . 

Wetting and cooking render certain foods more 
tender and more palatable, and when this secures the 
consumption of materials otherwise wasted these opera- 
tions may become economical. On the contrary, simi- 
lar treatment of grain foods alreadj' much liked by the 
animal is, according to the majority of testimony, an 
occasion of loss rather than of gain. 

Practice differs as to the number of portions into 
which the daily ration shall be divided. Some herds 



414 • The Feeding of Animals 

are fed three times a day and some twice. While it 
would be possible to feed too manj- times, or too 
much at any one time, it seems more than probable 
that if animals are fed regularly the ration may be 
as efficient when divided into two portions as when 
there are three feeding periods. The adaptation of 
any system to the requirements of farm work is a 
matter of more importance, probably, than any in- 
fluences proceeding from the number of feeding periods. 
The warming of the water consumed has been intro- 
duced to some extent with dairy herds. Certainly it is 
bad practice to force cows to drink ice-cold water, but 
it is also bad practice to warm the water above the 
point of palatableness. The likes and dislikes of 
animals must be considered, and to ignore them, even 
to save the small food expense necessary for warming 
the ingested water, is not advisable. 

QUANTITY OF THE RATION 

Great stress is usually laid upon the fact that it 
is only the food that is supplied above maintenance 
needs which is productive. This truth, indiscrimi- 
nately accepted, has led, the writer believes, to feed- 
ing so excessively as to injure the health of the 
animals and diminish profits. The largest production 
is not always the most profitable. Abundant testimony 
can be cited in support of the statement that very 
heavy rations yield smaller returns per unit of food 
consumed than more moderate ones. It is possible, 
also, to adopt an unprofitable extreme in the direction of 



Quantity of Ration — Management 415 

light feeding. Heavy rations are sometimes warranted 
by the low cost of feeds and the high price of the result- 
ing product, a condition which has not existed for 
the past ten years. In the writer's judgment milk is 
more economically produced by cows not unusual in 
character or size when the grain ration, wisely com- 
pounded, ranges between 8 and 12 pounds daily, 
according to the weight and capacity of the animal, 
than when more is fed, provided the coarse foods are 
supplied in the ordinary proportion. It is especially 
important with breeding animals, where the physical 
condition of the dam should be kept at its best, that 
the indigestion and high physical tension induced by 
extreme rations should be avoided. 

ENVIRONMENT AND TREATMENT OF ANIMALS 

The quarters in which animals live should be com- 
fortable, that is, they should be neither too warm nor 
too cold and should be well ventilated. These condi- 
tions are essential to health and the most profitable 
production. The stable temperature in winter should 
be held above 45° P. as a minimum, and may well be 
kept below 60°. A constant exchange of air should be 
secured without creating cold drafts, and the "King" 
system of ventilation seems to be worthy of com- 
mendation. 

All domestic animals, whether the milch cow or the 
fattening steer, should have a reasonable amount of 
exercise under comfortable conditions. Little sym- 
pathy should be shown towards the modern fad of 



416 The Feeding of Animals 

tying cows by their heads in one spot for five or six 
months, under the plea that exercise is work and work 
costs food. The statement had better be in accord- 
ance with the experience of all time, that exercise is 
health and vigor and that food is well used in main- 
taining these. The cow is more than a machine; she 
is a sentient being, susceptible to many of the influ- 
ences which are essential to the physical welfare of 
the human species. Let no one take this opinion as 
an excuse for the cruel and wasteful exposure of 
farm animals to inclement weather, which is so often 
observed, for this is simply a violation of the laws of 
kindness and economy in the other direction. 

A sympathetic relation should be established be- 
tween the animal and the herdsman. Close observers 
declare that such a relation promotes greater thrift 
and larger production, especially with dairy cows. 
These animals, possessed of the instincts and affec- 
tions of motherhood, respond to fondling through its 
influence upon their nervous organization. 

Moreover, the economic relation is not the only one 
man sustains to the animal world. Farm animals are 
man's companions and friends, for which he may enter- 
tain even sentiments of affection. The daily life of the 
farm-house is full of pleasant experiences that belong to 
the care of, and association with, the grateful creatures 
whose wants must be supplied, — the motherly cow, the 
faithful horse or the noisy, cackling fowl. No farmer 
has reached his best estate who does not find in the 
animal life about him an enjoyable companionship of 
which he need not be ashamed, and without a sense 



Kindness toward Animals 417 

of which he is not prepared to fulfil his obligations to 
the creatures dependent upon him. 

While it is the purpose of this volume to deal with 
the facts and principles of science and practice, it is 
not improper to briefly urge the need of the cultivation 
of right sentiment concerning kindness in the care of 
animals, for we really do not fully appreciate the unkind- 
ness shown by man toward the inferior species under 
his control. In no way has he more clearly demon- 
strated that he partakes of the brute nature than in 
his treatment of the brute. As a master he has been 
guilty of cruelty which it is humiliating to contemplate, 
a cruelty not as swift in its operation as that of the 
beast of prey, but which is greatly more shocking and 
is wholly at variance with the exalted characteristics 
that we attribute to humanity. The half- sheltered ani- 
mals that have endured our cold northern winters, the 
spavined, wind -broken wrecks of our livery stables, 
whose infirmities secure for them no relief from hard 
service, the daily exhibitions on our city streets of the 
patient draft horse with raw flesh under the collar and 
smarting under blows from unfeeling, cursing drivers, 
and especially the deliberately brutal practices of the 
race- track, where amid the plaudits of a throng of men 
and women who would claim to have kind hearts, noble 
animals, by unjustifiable "scoring" and in the subse- 
quent race, are often forced to the last limits of en- 
durance, are all evidences of an utterly selfish indiffer- 
ence to the suffering of living creatures that can neither 
utter a complaint nor avenge their wrongs. A certain 
proportion of humanity appears to regard the animal 

AA 



418 The Feeding of Animals 

as a mere unfeeling machine out of which pleasure and 
gain are to be forced even to the pound of flesh, and 
not as sentient beings capable of the keenest physical 
pain and with rights that should be respected. The 
constant occurrence of the ill-treatment of animals is 
perhaps the cause of the complaisance with which it is 
regarded, but it is no excuse for such thoughtless indif- 
ference. Society notes and punishes flagrant cases of 
abuse, but the average human conscience is not yet 
sufficiently tender toward man's treatment of his faith- 
ful servants. 



APPENDIX 

COMPOSITION AND DIGESTION TABLES 

1. Average composition of American feeding stuffs 

(pp. 419-427). 

2. Average coefficients of digestion (pp. 427-435). 

3. Feeding standards (pp. 435-438). 

4. Fertilizing constituents of American feeding stuffs 

(pp. 439-443). 

1. AVERAGE COMPOSITION OF AMERICAN 
FEEDING STUFFS 

The figures in the following table have been taken 
from Bulletin No. 11, Office of Experiment Stations ; 
Farmers' Bulletin No. 22, U. S. Department of Agricul- 
ture; Henry's Feeds and Feeding, Bulletin No. 81, Ver- 
mont Agricultural Experiment Station, and Bulletin No. 
166, New York State Agricultural Experiment Station. 

The percentages given represent averages from which 
there are material variations. These variations are 
mostly due to differences in the water content, the in- 
fluence of locality and of the stage of growth and the 
changes brought about by the methods and conditions 
of curing. They are not so large and important with 
the grains as with the fodders. 

(419) 



420 



Appendix 



Composition of Feeding Stuffs 

Nitrogen- No. of 

free ex- analy- 

Water Ash Protein Fiber tract Fat ses 

% % % % % % 

Green Fodder 

Corn fodder — * 

Flint varieties . . . 79.8 1.1 2. 4.3 12.1 .7 40 

Flint varieties cut 
after kernels had 
glazed 77.1 1.1 2.1 4.3 14.6 .8 10 

Dent varieties ... 79. 1.2 1.7 5.6 12. .5 63 

Dent varieties cut 

after kernels had 

glazed 73.4 1.5 2. 6.7 15.5 .9 7 

Sweet varieties . . 79.1 1.3 1.9 4.4 12.8 .5 21 

All varieties^. . . . 79.3 1.2 1.8 5.0 12.2 .5 126 

Leaves and husks, 

cut green .... 66.2 2.9 2.1 8.7 19. 1.1 4 

Stripped stalks, cut 

green 76.1 .7 .5 7.3 14.9 .5 4 

Sorghum fodder . . . 79.4 1.1 1.3 6.1 11.6 .5 11 

Rye fodder 76.6 1.8 2.6 11.6 6.8 .6 7 

Barley fodder . . . ..79. 1.8 2.7 7.9 8. .6 1 

Oat fodder 62.2 2.5 3.4 11.2 19.3 1.4 6 

Pasture grass .... 80. 2. 3.5 4. 9.7 .8 . . 

Redtop,t in bloom . .65.3 2.3 2.8 11. 17.7 .9 5 

Tall oat grass, t in 

bloom 69.5 2. 2.4 9.4 15.8 .9 3 

Orchard grass, in 

bloom . . . . 73. 2. 2.6 8.2 13.3 .9 4 

Meadow fescue, in 

bloom 69.9 1.8 2.4 10.8 14.3 .8 4 

Italian rye grass, com- 
ing into bloom . 73.2 2.5 3.1 6.8 13.3 1:3 24 

Timothy, § at different 

stages 61.6 2.1 3.1 11.8 20.2 1.2 56 

* Corn fodder is the entire plant, usually a thickly planted crop. Corn stiver 
is what is left after the ears are harvested. 

t Herd's grass of Pennsylvania. I Meadow Oat Grass. 

I Herd's grass of New England and New York. 



Composition 


of Feeding Stuffs 




421 




Water 


Ash 


Protein 


Fiber 


Nitrogen- 
free ex- 
tract 


Fat 


No. of 
analy- 
ses 


Green Fodder— continued 


% 


% 


% 


% 


% 


% 




Kentucky blue grass,* 
















at different stages 


65.1 


2.8 


4.1 


9.1 


17.6 


1.3 


18 


Hungarian grass . . . 


71.1 


1.7 


3.1 


9.2 


14.2 


.7 


14 


Japanese millet . . . 


75. 


1.5 


2.1 


7.8 


13.1 


.5 


12 


Red clover, at differ- 
















ent stages .... 


70.8 


2.1 


4.4 


8.1 


13.5 


1.1 


43 


Alsike clover, t in 
















bloom 


74.8 


2. 


3.9 


7.4 


11. 


.9 


4 


Crimson clover . . . 


80.9 


1.7 


3.1 


5.2 


8.4 


.7 


3 


Alfalfa, % at different 
















stages 


71.8 


2.7 


4.8 


7.4 


12.3 


1. 


23 


Serradella, at differ- 
















ent stages .... 


79.5 


3.2 


2.7 


5.4 


8.6 


.7 


9 


Cowpea . 


83.6 


1.7 


2.4 


4.8 


7.1 


.4 


10 


Soja bean 


75.1 


2.6 


4. 


6.7 


10.6 


1. 


27 


Horse bean .... 


84.2 


1.2 


2.8 


4.9 


6.5 


0.4 


2 


Flat pea {Lathyrus 
















sylvestris) .... 


66.7 


2.9 


8.7 


7.9 


12.2 


1.6 


2 


Rape 


84.5 


2. 


2.3 


2.6 


8.4 


.5 


2 



Silage 
Corn silage . . . 
Sorghum silage . 
Red clover silage 
Soja bean silage . 
Cowpea vine silage 
Field pea vine silage 
Silage of mixture of 
cowpea vines and 
soja bean vines . 
Millet and soja bean 
Corn and soja bean 

Rye 

Apple pomace . . . . 



79.1 
76.1 

72. 
74.2 
79.3 
50.1 



69.8 

79. 

76. 

80.8 
85. 



1.4 
1.1 

2.6 
2.8 
2 9 
3.5 



4.5 

2.8 

2.4 

1.6 

.6 



1.7 

.8 
4.2 
4.1 
2.7 
5.9 



3.8 
2.8 
2.5 
2.4 
1.2 



6. 
6.4 
8.4 
9.7 
6. 
13. 



9.5 
7.2 
7.2 
5.8 
3.3 



11. 

15.3 

11.6 
6.9 
7.6 

26. 



11.1 
7.2 

11.1 
9.2 



.8 
.3 
1.2 
2.2 
1.5 
1.6 



1.3 

1. 
.8 
.3 

1.1 



99 
6 
5 

1 
2 

1 



*June Grass. 



tSwedish Clover. 



JLucerne. 



422 Appendix 



Nitrogen- No. ot 

free ex- analy- 

Water Ash Protein Fiber tract Fat ses 

% % % % % % 

Hay and Dry Coarse Fodder 

Corn fodder,* field - 

cured 42.2 

Corn leaves, field - 

cured 30. 

Corn husks, field- 
cured 50.9 

Corn stalks, field- 
cured 68.4 

Corn stoverf field- 
cured 40.5 

Barley hay, cut in 

milk 15. 

Oat hay, cut in milk 15. 
Hay from — 

Redtop,J cut at dif- 
ferent stages . . 8.9 
Redtop, cut in bloom 8.7 
Orchard grass ... 9.9 
Timothy, § all analy's 13.2 4.4 

Timothy, cut in full 
bloom 15. 

Timothy, cut soon af- 
ter bloom .... 14.2 

Timothy, cut when 
nearly ripe . . . 14.1 

Kentucky blue grass 21.2 
Cut when seed was 

in milk 24.4 7. 6.3 24.5 34.2 3.6 4 

Cut when seed was 

ripe 27.8 6.4 5.8 23.8 33.2 3. 4 

Hungarian grass . . 7.7 6. 7.5 27.7 49. 2.1 13 

Meadow fescue . . 20. 6.8 7. 25.9 38.4 2.7 9 

Italian rye grass . . 8.5 6.9 7.5 30.5 45. 1.7 4 

* Entire plant. 

t What is left after the ears are harvested. 

X Herd's grass of Pennsylvania. 

§ Herd's grass of New England and New York. 



2.7 


4.5 


14.3 


34.7 


1.6 


35 


5.5 


6. 


21.4 


35.7 


1.4 


17 


1.8 


2.5 


15.8 


28.3 


.7 


16 


1.2 


1.9 


11. 


17. 


.5 


15 


3.4 


3.8 


19.7 


31.5 


1.1 


60 


4.2 


8.8 


24.7 


44.9 


2.4 


1 


5.2 


9.3 


29.2 


39. 


2.3 


1 


5.2 


7.9 


28.6 


47.5 


1.9 


9 


4.9 


8. 


29.9 


46.4 


2.1 


3 


6. 


8.1 


32.4 


41. 


2.6 


10 


4.4 


5.9 


29. 


45. 


2.5 


68 


4.5 


6. 


29.6 


41.9 


3. 


12 


4.4 


5.7 


28.1 


44.6 


3. 


11 


3.9 


5. 


31.1 


43.7 


2.2 


12 


6.3 


7.8 


23. 


37.8 


3.9 


10 



Composition 


of Feeding Stuffs 




423 




Water 


Ash 


Protein 


Fiber 


Nitrogen- 
free ex- 
tract 


Fat 


No. of 
Analy- 
ses 


% 

Hay and Dry Coarse Fodder 
—continued 


% 


% 


% 


% 


% 




Hay from — 
















Perennial rye grass 


. 14. 


7.9 


10.1 


25.4 


40.5 


1.7 


4 


Mixed grasses . . 


. 15.3 


5.5 


7.4 


27.2 


42.1 


2.5 


126 


Rowen (mixed)* . 


. 16.6 


6.8 


11.6 


22.5 


39.4 


3.1 


23 


Mixed grasses anc 
clovers .... 


I 

12.9 


5.5 


10.1 


27.6 


41.3 


2.6 


17 


Swamp hay . . . 


. 11.6 


6.7 


7.2 


26.6 


45.9 


2. 


8 


Salt marsh . . . 


. 10.4 


7.7 


5.5 


30. 


44.1 


2.4 


10 


Red clover . . . 


. 15.3 


6.2 


12.3 


24.8 


38.1 


3.3 


38 


Red clover in bloon 


l 20.8 


6.6 


12.4 


21.9 


33.8 


4.5 


6 


Alsike clover . . 


9.7 


8.3 


12.8 


25.6 


40.7 


2.9 


9 


White clover . . 


9.7 


8.3 


15.7 


24.1 


39.3 


2.9 


7 


Crimson clover 


. 9.6 


8.6 


15.2 


27.2 


36.6 


2.8 


7 


Japan clover . . 


. 11. 


8.5 


13.8 


24. 


39. 


3.7 


2 


Vetch 


11.3 


7.9 


17. 


25.4 


36.1 


2.3 


5 


Serradella . . . 


9.2 


7.2 


15.2 


21.6 


4i.2 


2.6 


3 


Alfalfat .... 


8.4 


7.4 


14.3 


25. 


42.7 


2.2 


21 


Cow pea 


10.7 


7.5 


16.6 


20.1 


42.2 


2.2 


8 


Soja bean .... 


11.3 


7.2 


15.4 


22.3 


38.6 


5.2 


6 


Flat pea ( Lathy ru& 
sylcestris) .... 


8.4 


7.9 


22.9 


26.2 


31.4 


3.2 


5 


Peanut vines (with- 
out nuts) . . . 


7.6 


10.8 


10.7 


23.6 


42.7 


4.6 


6 




15. 


6.7 


13.7 


24.7 


37.6 


2.3 


1 


Soja -bean straw . . 


. 10.1 


5.8 


4.6 


40.4 


37.4 


1.7 


4 


Horse-bean straw . 


. 9.2 


8.7 


8.8 


37.6 


34.3 


1.4 


1 


Wheat straw . . . 


. 9.6 


4.2 


3.4 


38.1 


43.4 


1.3 


7 


Rye straw ... 


. 7.1 


3.2 


3. 


38.9 


46.6 


1.2 


7 


Oat straw 


9.2 


5.1 


4. 


37. 


42.4 


2.3 


12 


Buckwheat straw . 


. 9.9 


5.5 


5.2 


43. 


35.1 


1.3 


3 


Roots and Tubers 


















78.9 


1. 


2.1 


.6 


17.3 


.1 


12 


Sweet potatoes . . 


. 71.1 


1. 


1.5 


1.3 


24.7 


.4 


6 


* Second 


cut. 






tLucerne. 







424 



Appendix 



Water 

% 
Boots and Tubers— cont'd 

Red beets 88.5 

Sugar beets 86.5 

Mangel-wurzels ... 90.9 

Turnips ...... 90.5 

Rutabagas 88.6 

Carrots 88.6 

Artichokes 79.5 

Grains and Other Seeds 

Corn kernel — 

Dent, all analyses . 10.6 

Flint, all analyses . 11.3 

Sweet, all analyses. 8.8 

Pop varieties . . . 10.7 

Soft varieties ... 9.3 

All varieties and 

analyses .... 10.9 

Sorghum seed .... 12.8 

Barley 10.9 

Oats 11. 

Rye 11.6 

Wheat- 
Spring varieties . . 10.4 

Winter varieties, all 

analyses .... 10.5 

All varieties . . . 10.5 

Rice 12.4 

Buckwheat 12.6 

Sunflower seed ( whole) 8 . 6 

Flaxseed 9.2 

Cottonseed (whole, 

with hulls) . . . 10.3 

Cottonseed kernels 

(without hulls) . 6.2 

Cottonseed whole, 

roasted .... 6.1 



Ash 


Protein 


Fiber 


Nitrogen- 
free ex- 
tract 


Fat 


No. of 
analy- 
ses 


% 


% 


% 


% 


% 




1. 


1.5 


.9 


8. 


.1 


9 


.9 


1.8 


.9 


9.8 


.1 


19 


1.1 


1.4 


.9 


5.5 


.2 


9 


.8 


1.1 


1.2 


6.2 


.2 


3 


1.2 


1.2 


1.3 


7.5 


.2 


4 


1. 


1.1 


1.3 


7.6 


.4 


8 


1. 


2.6 


.8 


15.9 


.2 


2 


1.5 


10.3 


2.2 


70.4 


5. 


86 


1.4 


10.5 


1.7 


70.1 


5. 


68 


1.9 


11.6 


2.8 


66.8 


8.1 


26 


1.5 


11.2 


1.8 


69.6 


5.2 


4 


1.6 


11.4 


2. 


70.2 


5.5 


5 


1.5 


10.5 


2.1 


69.6 


5.4 


208 


2.1 


9.1 


2.6 


69.8 


3.6 


10 


2.4 


12.4 


2.7 


69.8 


1.8 


10 


3. 


11.8 


9.5 


59.7 


5. 


30 



1.9 10.6 1.7 72.5 1.7 6 

1.9 12.5 1.8 71.2 2.2 13 

1.8 11.8 1.8 72. 2.1 262 

1.8 11.9 1.8 71.9 2.1 310 

.4 7.4 .2 79.2 .4 10 

2. 10. 8.7 64.5 2.2 8 

2.6 16.3 29.9 21.4 21.2 2 
4.3 22.6 7.1 23.2 33.7 50 

3.5 18.4 23.2 24.7 19.9 5 

4.7 31.2 3.7 17.6 36.6 2 
5.5 16.8 20.4 23.5 27.7 2 



Composition of Feeding Stuffs 425 

Nitrogen- No. of 

free ex- analy- 

Water Ash Protein Fiber tract Fat ses 

% % % % % % 
Grains and Other Seeds- 
continued 

Peanut kernel (with- 
out hulls) .... 7.5 2.4 27.9 7. 15.6 39.6 7 

Horse bean 11.3 3.8 26.6 7.2 50.1 1. 1 

Soja bean 10.8 4.7 34. 4.8 28.8 16.9 8 

Cowpea 14.8 3.2 20.8 4.1 55.7 1.4 5 

Mill Products 

Corn meal 15. 1.4 9.2 1.9 68.7 3.8 77 

Corn and cob meal . . 15.1 1.5 8.5 6.6 64.8 3.5 7 

Oatmeal 7.9 2. 14.7 .9 67.4 7.1 6 

Barley meal 11.9 2.6 10.5 6.5 66.3 2.2 3 

Rye flour 13.1 .7 6.7 .4 78.3 .8 4 

Wheat flour, all analy's 12.4 .5 10.8 .2 75. 1.1 20 

Buckwheat flour . . . 14.6 1. 6.9 .3 75.8 1.4 4 

Ground linseed . . 8.1 4.7 21.6 7.3 27.9 30.4 2 

Pea meal 10.5 2.6 20.2 14.4 51.1 1.2 2 

Soja-bean meal . . . 10.8 4.5 36.7 4.5 27.3 16.2 1 
Ground corn and oats 

equal parts ... 13. 2.2 10.5 5.7 64.2 4.4 

Waste Products 

Corncob 10.7 1.4 2.4 30.1 54.9 .5 18 

Homiuy chops .... 11.1 2.5 9.8 3.8 64.5 8.3 12 

Corn bran 9.1 1.3 9. 12.7 62.2 5.8 5 

Corn germ 10.7 4. 9.8 4.1 64. 7.4 3 

Corn -germ meal . . . 8.1 1.3 11.1 9.9 62.5 7.1 6 
Gluten meal — 

Cream 10.1 .8 33.7 1.7 51.1 2.6 . . 

Chicago* 12.3 1.3 36.5 1.4 45.8 2.7 . . 

King 7.4 .5 33.7 1.2 52.6 4.6 . . 

Gluten feed 7.8 1.1 24. 5.3 51.2 10.6 11 

Buffalo* 9.6 2.3 27.1 6.7 51.1 3.2 . . 

Peoria* 7.5 .8 19.8 8.2 51.1 12.6 1 

Diamond, or Rock- 
ford 8.9 .8 23.6 6.6 56.6 3.5 . . 

*Included in above average. 



426 



Appendix 



Water 

% 
Waste Products— continued 

Chicago maize feed . 9.1 

Glucose feed arid glu- 
cose refuse . . . 6.5 

Dried starch feed and 

sugar feed . . . 10.9 

Starch feed, wet . . . 65.4 

Oat hulls 7.3 

Oat feed 7.7 

Barley screenings . . 12.2 

Malt sprouts .... 5. 

Brewers' grains, wet . 75.7 

Brewers' grains, dried 8.2 

Grano gluten _ . . . 5.8 

Rye bran 11.6 

Rye shorts 9.3 

Wheat bran from 

spring wheat . . 11.5 

Wheat bran from 

winter wheat . . 12.3 

Wheat bran, all an'ses 11.9 

Wheat middlings . . 10. 

Wheat shorts . . . . 11.8 

Wheat screenings . . 11.6 

Rice bran 9.7 

Rice hulls 8.2 

Rice polish 10. 

Buckwheat hulls . . . 13.2 

Buckwheat bran . . . 10.5 

Buckwheat middlings 13.2 

Cottonseed meal . . 6.8 

Cottonseed hulls . . 11.1 

Lins'd meal, old proc's 8.3 

Lins'd meal, new proc's 10. 

Peanut meal 10.7 

Peanut hulls .... 9. 



Ash 


Protein 


Fiber 


Nitrogen- 
free ex- 
tract 


No. of 

analy- 
Fat ses 


% 


% 


% 


% 


% 




.9 


22.8 


7.6 


52.7 


6.9 


3 


1.1 


20.7 


4.5 


56.8 


10.4 


2 


.9 


19.7 


4.7 


54.8 


9. 


4 


.3 


6.1 


3.1 


22. 


3.1 


12 


6.7 


3.3 


29.7 


52.1 


1. 


. . 


3.7 


16. 


6.1 


59.4 


7.1 


4 


3.6 


12.3 


7.3 


61.8 


2.8 


2 


6.4 


27.6 


10.9 


47.1 


3. 


. . 


1. 


5.4 


3.8 


12.5 


1.6 


15 


3.6 


19.9 


11. 


51.7 


5.6 


3 


2.8 


31.1 


12. 


33.4 


14.9 


1 


3.6 


14.7 


3.5 


63.8 


2.8 


7 


5.9 


18. 


5.1 


59.9 


2.8 


1 


5.4 


16.1 


8. 


54.5 


4.5 


10 


5.9 


16. 


8.1 


53.7 


4. 


7 


5.8 


15.4 


9. 


53.9 


4. 


88 


3.8 


17.4 


5.2 


58. 


5.6 




4.6 


14.9 


7.4 


56.8 


4.5 


12 


2.9 


12.5 


4.9 


65.1 


3. 


10 


10. 


12.1 


9.5 


49.9 


8.8 


5 


13.2 


3.6 


35.7 


38.6 


.7 


3 


6.7 


11.7 


6.3 


58. 


7.3 


4 


2.2 


4.6 


43.5 


35.3 


1.1 


2 


3. 


12.4 


31.9 


38.8 


3.3 


2 


4.8 


28.9 


4.1 


41.9 


7.1 


3 


6.2 


45.6 


5.4 


25.2 


10.8 




2.8 


4.2 


46.3 


33.4 


2.2 


20 


5.3 


35.7 


7.5 


36. 


7.2 


. . 


5.2 


36.1 


8.4 


36.7 


3.6 




4.9 


47.6 


5.1 


23.7 


8. : 


2,480 


3.4 


6.6 


64.3 


15.1 


1.6 


5 



Digestibility of Feeding Stuffs 



427 



Water 

% 
Miscellaneous 

Acorns 55.3 

Apples ........ 80.8 

Apple pomace .... 76.7 

Beet pulp 89.8 

Beet molasses . . . . 20.8 

Cabbage 90.5 

Prickly comfrey . . 88.4 

Pumpkin (field) . . . 90.9 

Sugar beet leaves . . 88. 



Ash 


Protein 


Fiber 


Nitrogen- 
free ex- 
tract 


Fat 


No. of 

analy- 
ses 


% 


% 


% 


% 


% 




1. 


2.5 


4.4 


34.8 


1.9 




.* 


.7 


1.2 


16.6 


.4 




.5 


1.4 


3.9 


16.2 


1.3 


7 


.6 


.9 


2.4 


6.3 


. . 


16 


10.6 


9.1(1 


f) . . 


59.5 


. . 


35 


1.4 


2.4 


1.5 


3.9 


.4 


2 


2.2 


2.4 


1.6 


5.1 


.3 


41 


.5 


1.3 


1.7 


5.2 


.4 


. . 


2.4 


2.6 


2.2 


4.4 


.4 





2. AVERAGE COEFFICIENTS OF DIGESTION 



The coefficients of digestion which follow are mostly 
taken from the compilation by Jordan and Hall as pub- 
lished in Bulletin No. 77, Office of Experiment Stations. 
Others, marked G, are from the compilation of Dietrich 
and Konig (Composition and Digestibility of Cattle 
Foods, Vol. II). 

Digestion by Ruminants 



No. ex- 
perim'ts 



Kind and condi- 
tion of food 



Dry Organic 
matter matter Ash 

% % % 



Digestion coefficients 

Nitrogen- 
Pro- free ex- 

tern Fiber tract 



GREEN FODDERS 
Meadow Grasses 

3 . Hungarian 67.2 68.6 52.2 64.3 

4 . Barnyard millet . . 66.6 67. 59.5 61.5 

1 . Timothy 63.5 65.6 32.2 48.1 

1 . Timothy rowen . . . 64.8 66.4 45.2 71.7 

1 . Pasture grass . . . 68.7 70. 49.7 65.5 

1 . Mixed-grass rowen . 65.6 67.4 46.2 67.4 



<& 



71.2 
66.5 
55.6 
63.8 
74.3 
62.6 



Fat 

% 



67.9 
68.3 
65.7 
67.8 
72.5 
71.6 



65.7 
64.3 
53.1 
£2.9 
54.7 
55.2 



428 Appendix 



-Digestion coefficients- 



Nitrogen- 

No. ex- Kind and condi- Dry Organic Pro- free ex- 

perim'ts tion of food matter matter Ash tein Fiber tract Fat 

% % % % % % % 
Cereal Plants 

2 . Barley . . ... 65.9 67.5 54.4 71.8 60.8 71.2 59.9 

8 . Dent corn, immature 68.8 70.7 45.4 65.2 66.6 73. 72. 
6 Dent corn, mature . 66.6 68.5 19.4 52.3 51.6 74.7 77. 

14 . Dent corn, all samples 67.8 69.8 35.6 59.7 60.2 73.7 74.1 

6 . Sweet corn .... 71.1 72.2 55.3 64. 62.9 76.6 75.6 

3 . Oats 59.5 60.9 53.4 71.8 52.8 62.6 69.2 

1 . Rye 73.4 75.3 55.8 79.4 79.2 70.1 74.5 

2 . Sorghum 67.3 69. 42.4 46.8 59. 74.6 74.2 

Glovers and Legumes 

6 . Alfalfa (G) 64. . . 81. 41. 72. 45. 

1 . Crimson clover . . . 67.9 69.1 56.1 77.1 56.1 74.5 66.5 

1 . Red clover .-. . . . 66.1 68.1 55. 67. 52.6 77.6 64.5 

1 . Red clover, before 

bloom (G) ...!.. 74. . . 74. 60. 83. 65. 

2 . Red clover, beginning 

bloom (G) 71. • . 74. 57. 79. 71. 

2 . Red clover, bloom to 

end (G) 61. . . 64. 44. 71. 53. 

1 . Red clover rowen . . 59.3 60.8 43.4 61.9 52.5 65.3 60.8 

1 . Canada peas .... 68.4 71.3 42.3 82. 62.4 71. 52.4 

2 . Cow pea 68.3 74.1 22.8 75.6 59.6 80.6 59.4 

4 . Soy bean 59.8 64.5 18.9 75.1 47. 73.2 54.1 

1 . Common vetch . . . 61.8 65.7 17.3 71.4 44.2 76.1 58.6 

3 . Hairy vetch .... 70.3 73.1 45.1 82.8 61.1 76.3 71.6 

Mixed 

1 . Barley and peas . . 53.4 60.2 46.2 77.2 43.5 61.4 59.7 

4 . Oats and peas . . . 65.4 67.2 45.4 76.1 59.7 67.7 67.7 
1 . Vetch and oats . . . 67. 68.4 52.7 74.8 68.3 67.9 47.2 

SILAGE 
Maize 

9 . Dent corn 65.1 67.1 32.2 49.3 66.7 68.6 80. 

6. Flint corn 73.1 76.1 32.9 62.8 75.1 76.9 81.8 

13 . Dent corn, immature 65.6 67.4 34.3 51.3 70.6 67.4 80.2 



Digestibility of Feeding Staffs 



429 



No. ex- Kind and condi- 
perim'ts tion of food 


Dry 
matter 


Digestion coefficients 

Nitrogen 
Organic Pro- free ex- 
matter Ash tein Fiber tract 


Fat 




Maize— continued 


% 


% 


% 


% 


% 


% 


% 


10 . 


Dent and flint corn, 


















mature 


70.8 


73.6 


30.3 


56. 


70. 


76.1 


82.4 


1 . 


Sweet corn 

Miacellaiieous 


68.1 


70.1 


31.9 


54. 


71.1 


71.8 


83.5 


1 . 


Cow pea .... 


59.6 


63.4 


30.3 


57.5 


52. 


72.5 


62.6 


1 . 


Soy bean (steers) 


49.8 


53.8 


28. 


55.3 


42.9 


61.2 


48.9 


1 . 


Soy bean (groats) 


59. 


59.3 


56.7 


75.7 


54.8 


52. 


71.9 


1 . 


Corn and soy bean . 


69. 


71. 




65. 


64.8 


74.9 


82.1 


1 . 


Millet and soy bean 


58.8 


59.9 




58.4 


69.4 


59.2 


72.2 



Corn, horse beans, 
and sunflower 
heads 

Corn, horse beans, 
and sunflower 
plants 



65.6 67.8 41.1 62.7 60.1 72.4 76.7 



65.5 69.3 25.6 58. 65.3 73.7 74.1 



DRIED FODDERS 

Meadow Grasses 

Black grass (Juncns 
bulbosus) .... 

Black grass (Juncus 

gerardi) 

Blue joint .... 

Branch grass (Spar- 
tina stricta glabra) 

Branch grass (Dis- 
ticJtli/s spicata) . . 

Chess or cheat . . 

Crab grass .... 

Fox grass (Spartina 
patens) 

Fox grass (Spartma 
jiincea, etc.) . . . 

Flat sage 

Hungarian grass . . 

Johnson grass . . . 



59.5 


• • 




63. 


60.5 


57. 


41.5 


53.4 


52.1 


69. 


54.3 


57.4 


49. 


45.7 


54.3 


55.8 


29.4 


63.4 


54.5 


55.9 


44.7 


56. 


• • 


• • 


62.5 


52. 


54. 


32. 


49.7 


48.9 


58.1 


51.7 


56.4 


45.7 


36.6 


45. 


47.3 


23. 


42. 


46. 


49. 


32. 


53.6 


55. 


37.6 




59.1 


54.5 


46.8 


54.8 


54.5 


58.2 


59.3 


57.4 


53.1 


36.4 


53. 






57. 


51. 


52. 


24. 


56.1 


57.3 


62. 


51.8 


60.4 


55.1 


36.1 


65. 


66.3 


47.4 


60. 


67.6 


67.1 


63.9 


56.5 


58.3 


30.5 


41.4 


65.7 


56.9 


38.4 



430 



Appendix 



-Digestion coefficients- 



No. ex- Kind and condi- Dry Organic 

perim'ts tion of food matter matter Ash 

% % % 

Meadoiv Grasses— continued 



1 
1 

2 

2 

1 

17 

3 

4 
1 
2 

2 
1 



2 
1 
1 
1 
2 

1 

17 

7 

13 

10 

3 
5 



57.4 

62.3 

56.6 

59.7 

46. 

56.6 



56.8 
61.6 
57.8 
61.2 

48.5 
57.9 



Barnyard millet . 

Cat-tail millet . . 

Orchard grass . . 

Redtop 

Redtop and sedge 

Timothy .... 

Timothy, before or 
in bloom .... 

Timothy, past bloom 

Timothy rowen . . 

Wild-oat grass . . 

Witch grass .... 

Black grass and red- 
top (cove mixture) 

Mixed grasses . . . 

Meadow hay — 

Best (G) .... 

Medium (G) 61. 

Poor (G) 56. 

Pasture grass . . . 72.6 73.2 

Swale hay 39. . . 

High grown salt hay 53. 
Salt-hay mixture . . 56.4 54.9 
Rowen hay .... 64.4 65.8 



60.7 

53.4 

62.2 

64. 

61.2 

54.6 
57.1 



61.5 
54.5 
64.4 
65.2 
62.3 

54.3 

58.8 

67. 



Cereal Plants 

Barley hay ... 61.2 

Dent corn fodder . 64.3 

Flint corn fodder . 68.6 
Dent and flint corn 

fodders (immature) 63.9 
Dent and flint corn 

fodders (mature) . 68.2 

Sweet corn fodder . 67.2 

Corn stover . . . . 57.2 



62.3 
66.1 
71.7 



63.1 
68.4 

29. 
10.1 

32.8 

44.2 
30.3 
56.4 
34.7 
40.9 

57.5 



51.8 



69.8 
46.6 

44.8 
30.7 
42.6 



Pro- 
tein 



63.7 
62.6 
59.5 
61.3 
37.2 
46.9 

56.8 

45.1 

68. 

58.3 

58.6 

47.9 
58.5 

65. 

57. 

50. 

73.4 

34. 

63. 

42.6 

69.1 

65.2 
50.4 
60. 



Fiber 

% 

61.6 
66.5 
60.4 
61.3 
55.7 
52.5 

58.8 
47.1 
66.5 
67.9 
62.8 

59.7 
59.7 

63. 

60. 

56. 

76.1 

33. 

50. 

60.7 

66.6 

61.7 
62.2 
74.9 



Nitrogen- 
free ex- 
tract 



51.6 
59.1 
55.4 
61.9 
45.6 
62.3 



64, 
60, 
63, 
65, 



65.6 

53.2 

58.7 

68. 

64. 

59. 

74.2 

46. 

53. 

54.7 

66.2 

63.3 

68. 
70.3 



Fat 

% 

46.3 

46.1 

53.8 

50.5 

49. 

52.2 

58.4 
51.9 
49.5 
50.5 
57.2 

40.3 

48.5 

57. 

53. 

49. 

67.3 

44. 

47. 

29.7 

47.4 

40.5 
73.6 
71.4 



65.7 37.2 51.7 66. 66.2 72.2 



70.7 


30.6 56.1 


65.8 72.2 


73.9 


69.8 


35.6 64.1 


73.8 68.2 


73.6 


59.1 


32.6 35.9 


64.2 57.9 


70.4 



Digestibility of Feeding Stuffs 



431 



-Digestion coefficients- 



No. ex- 
perim'ts 



Kind and condi- 
tion of food 



Dry Organic 
matter matter Ash 



Cereal Plants — continued 



% 



3 . New corii product . 58.1 
2 . Topped corn fodder 57.4 

1 . Corn blades and 

husks 63.8 

2 . Corn leaves (pulled 

fodder) 59.8 

1 . Corn husks .... 72. 

1 . Corn butts 66.5 

1 . Oat hay 49.3 

1 . Oat straw 50.3 

Bean straw 

Wheat straw (G) .... 

Rye straw (G) 

Barley straw (G) 

Rice straw (G) . = . 
1 . Sorghum fodder 

(pulled) 63.1 

1 . Sorghum bagasse . 60.6 



% 

59.2 
62.3 



Clovers 
2 . Alsike clover . . 
4 . Crimson clover 
6 . Red clover . . . 
2 . Red clover rowen 
1 . White clover . . 



Nitrogen- 
Pro- free ex- 
tern Fiber tract 



Fat 



38.7 46.7 57. 60.5 78.2 
3.8 38.7 71. 57.9 67.4 



67.1 22.6 47.7 72.9 66.4 58.1 



63.6 


26. 8 


43.4 


67.5 


63. 


59.9 


74.2 


16. 


29.5 


79.5 


75. 


32.5 


69.4 


11.5 


21. 


73.5 


69. 


79.5 


50.1 


34.6 


54.2 


43.5 


52. 


61.9 


52. 




. 


57.6 


53.2 


38.3 


55. 




49. 


43. 


67. 


57. 


46. 




23. 


55. 


39. 


36. 


48. 




25. 


63. 


39. 


29. 


53. 




25. 


55. 


54. 


42. 


47. 




45. 


57. 


32. 


47. 


64.8 


29.5 


60.8 


70 4 


64.5 


46.7 


62.2 


13.4 


13.7 


63.8 


64.8 


46.4 



62.3 63.2 52.2 66.1 53.5 70.7 50.2 
58.1 59.1 51.9 68.7 46.7 64.6 43.4 

57.4 59.7 29.1 58. 54.2 64.4 55.2 
58. 59.1 45.8 64.8 47.4 62.8 59.8 
66. 66.6 58.5 73.2 60.6 69.5 50.6 



Legumes other than Clovers 

3 . Alfalfa 58.9 60.7 39.5 72. 

1 . Cow pea vine . . . 59.2 60. 49.5 64.8 

1. Peanut vine .... 59.9 63.1 20.4 63.3 

1. Soy bean 62.4 63.9 . . 71.1 

1. Hairy vetch .... 69.4 71.8 42.2 82.3 

Bean straw (G) .... 55. . . 49. 

Pea straw, good (G) . . 59. . . 60. 



46. 

42. 

51.9 

60.8 

61.1 

43. 



69.2 
70.6 
69.5 
68.8 
72.9 
67. 



51. 

51.8 

65.9 

29.2 

70.3 

57. 



52. 64. 46. 



432 



No. ex- 
perim'ts 



Appendix 



-Digestion coefficients- 



Kind and condi- 
tion of food 



Miscellaneous and Mixed 
1 . Buttercup hay . . 

1 . Whiteweed hay . 

2 . Clover and timothy 
1 . Vetch and oats . . 



Dry Organic 

matter matter Ash 

% % % 

56.1 56.6 

57.8 58.3 

54.6 53.2 

58.1 58.7 



Grains and Seeds 

Barley (G) 86. 

Oats (G) 71. 

5 . Corn meal 89.4 89.6 

2 . Corn - and -co*b meal . 78.7 79.8 

1 . Rye meal 87.3 88.7 

1 . Pea meal 86.8 87.9 

Field beans~ 89. 

1 . Soy-bean meal . . . 81.9 84. 

1 . Cottonseed, raw . . 66.1 65.8 

1 . Cottonseed, roasted 55.9 56.8 

Linseed 77. 

Acorns 88. 



48.1 
52. 



43. 



43. 



Pro- 
tein 

% 

56.3 
58.4 
42.3 
59.7 



70. 

78. 

67.9 

55.6 

84.4 

83.2 

88. 

91 1 

67.8 

46.9 

91. 

83. 



Fiber 

% 

41.1 
45.5 
49.6 
66. 



26. 



45.7 

25.7 

72. 

71.2 

75.5 

65.9 

60. 

62. 



Nitrogen - 
free ex- 
tract 

% 

66.9 
66 7 
57.5 
54.2 



92. 

77. 

94.6 

87.6 

91.9 

93.6 

92. 

76.3 

49.6 

51.4 

55. 

91. 



Fat 

% 

69.7 
62. 

54. 
18.6 



89. 

83. 

92.1 

84.1 

64.2 

54.5 

81. 

85.7 

87.1 

71.7 

86. 

87. 



BY-PRODUCTS 
Cereals 

1 . Atlas meal 79.6 83.4 

1 . Cerealine feed . . . 90.4 92.7 

2 . Corncobs 51.4 

1 . Dried brewers' grains 61.6 65.4 

5 . Gluten feed .... 86.3 87.3 

4 . Gluten meal .... 89.7 90.4 

1 . H. O. dairy feed . . 65.3 68. 

1 . H. O. horse feed . . 70.1 72.6 

1 . Maize feed .... 87.1 87.1 

1 . Malt sprouts .... 67.1 67.2 

1 . Quaker oat feed . . 62. 65.3 

1 . Victor corn -and- oat 

feed 74.7 77.4 



72.8 


105.7 


84.5 


91.2 


76.6 


82.2 


95.3 


80.6 


19.3 


57.5 


48.3 




79.3 


52.6 


57.8 


91.1 


85.6 


78. 


89.2 


84.4 


88.2 




89.8 


94.4 


77.8 


40.8 


69.9 


85.5 


74.4 


35.2 


78.7 


84. 


85.5 


82.5 


87.9 


91.5 


80.2 


32.9 


68.1 


104.6 


81.1 


42.6 


67.4 


89. 



70.8 48.3 83. 



86.8 



Digestibility of Feeding Stuffs 433 



-Digestion coefficients- 



Nitrogen- 

No. ex- Kind and condi- Dry Organic Pro- tree ex- 

perim'ts tion of food matter matter Ash tein Fiber tract Fat 

% % % % % % % 
Ce rea I — continued 

7 . Wheat bran .... 62.3 65.7 . . 77.8 28.6 69.4 68. 

1. Wheat bran and 

shorts 60.2 60.7 7.5 75.8 18.3 64.3 45. 

3 . Wheat middlings . . 75. 78.5 . . 79.8 33.1 81.3 86.3 

Oil-bearing Seeds 

3 . Cottonseed hulls . . 39.8 40.5 23.2 . . 40. 41.1 85.7 

5 . Cottonseed meal . . 73.7 76.1 23.7 88.4 55.5 60.6 93. 2 

1 . Linseed meal, old 

process 78.7 81.2 . . 88.8 57. 77.6 88.6 

2 . Linseed meal, new 

process 79.2 81.8 . . 85.2 80.4 86.1 96.6 

Miscellaneous 

1. Peanut feed .... 32.1 32.8 . . 70.6 11.7 49.1 89.7 

1 . Rice meal 73.8 81.6 . . 61.9 . . 92.3 91.1 



ROOTS 

1 . Mangolds . . . 

1 . Potatoes, raw . 
1 . Potatoes, boiled 

1 . Rutabagas . . . 

1 . Sugar beets . . 

1 . Turnips . . . . 



78.5 84.8 16.4 74.7 42.8 91.3 . . 

75.7 77. . . 44.7 . . 90.4 13. 

80.1 81.2 . . 43.4 . . 92.1 . . 

87.2 91.1 31.2 80.3 74.2 94.7 84.2 
94.5 98.7 31.9 91.3 100.7 99.9 49.9 

92.8 96.1 58.6 89.7 103. 96.5 87.5 



ANIMAL PRODUCTS 

Cow's milk (G) 98. . . 94. . . 98. 100. 

Meat meal (G) 93. . . 96 99. 

Dried blood (G) .... 63. . . 62. . . 100. 100. 

Dried fish, ground(G) 90 76. 



Digestion hy Horses 
Dried Fodders 

Timothy hay in full 

bloom, well cured . 43.5 
New corn product . 49.9 

BB 



44.1 


34. 


21.2 


42.6 47.3 47.3 


51.7 


21.7 


67.5 


54.6 46.9 59.8 



434 



Appendix 



-Digestion coefficients- 



No. ex- 
perfrn'ts 



Kind and condi- 
tion of food 



Dried Fodders— continued 
Meadow hay — 

Best (G) ... 

Medium (G) . . 

Poor (G) ... 
Red clover hay(G) 
Alfalfa hay (G) . 
Wheat straw ^G) . 



Dry 
matter 

% 



Organic 
matter 



58. 
50. 
46. 
51. 
58. 
21. 



Ash 



Roots 

Potatoes (G) 93. 

Carrots (G) 87. 



Grains 
Oats (G)' ... 
Barley (G) . . 
Corn (G) . . 
Field beans (G) 
Peas (G) .... 
Dent corn, unground 74.4 

Corn meal, same 
material, ground . 88.4 

White oats, first 
quality, unground 72.4 

Oats, same material, 

ground 75.7 



69. 

87. 
89. 
87. 
80. 
75.3 



74.1 



U .1 



26.3 

33.1 
29.2 



Pro- 
tein 



63. 

57. 
55. 
56. 
73. 

28. 

88. 
99. 

79. 

80. 
76. 
86. 
83. 
57.8 

75.6 

86.1 



Fiber 

% 



48. 
39. 
38. 
37. 
40. 
18. 



29. 

40. 
65. 

8. 

(?) 

(?) 
31.1 



82.4 14.4 



Nitrogen- 
free ex- 
tract 



65. 

58. 
52. 
63. 

70. 

28. 

99. 
94. 

75. 

87. 
92. 
94. 

89. 
88.2 

95.7 

79.4 

86.1 



Fat 



22. 
18. 
24. 
29. 
14. 
66. 



71. 
42. 
61. 
13. 

7. 
47.7 

73.1 

82.4 
79.9 



Digestion by Swine 
Grains and Seeds 

1 . Barley, whole kernel 80.1 80.3 5.4 

1 . Flint corn, unground 82.5 83.4 . . 

1 . Flint corn, unground 89.7 91.3 

1 . Corn meal, same 
material, finely 
ground 89.5 91.2 . . 

1 . Corn-and-cob meal, 

whole ear ground. 75.6 76.7 



81.4 


48.7 


86.6 


57. 


68.7 


38.3 


88.8 


45.6 


89.9 


48.7 


93.9 


77.6 


86.1 


29.4 


94.2 


81.7 


75.7 


28.5 


83.6 


82. 



Feeding Standards 



435 



No 
peri 


. ex- Kind and condi- 
m'ts tion of food 

Grams and Seeds — con- 
tinued 


Dry 
matter 

% 


jjigesu< 

Organic 
matter Ash 

% % 


on coen 

Pro- 
tein 

% 


lcieius- 

Nitrogen 
free ex- 
Fiber tract 

% % 


Fat 

% 


? 


. Wheat, unground 


. 72. 


. . 


44. 


70. 


30. 


74. 


60. 


? 


. Wheat, cracked . 


. 82. 


. . 


50. 


80. 


60. 


83. 


70. 


1 


. Peas, ground . . 
By-products 


. 89.8 


91.5 


40.3 


88.6 


77.9 


95.1 


50. 


1 


. Wheat bran . . . 


. 65.8 


. . 


. . 


75.1 


33. 


65.5 


71.8 




Rye bran (G) . . 




67. 




66. 


9. 


74. 


58. 


2 , 


. Wheat shorts . . 


. 76.5 




5.4 


73.5 


36.5 


86.8 




2 


. Linseed meal . . 
Roots 


. 77.5 


• • 


10. 


86. 


12. 


85. 


80. 


2 . 


. Potatoes, raw . . 


. 97. 


. 


44.6 


84.5 


. . 


98.1 


. . 


2 


Potatoes, cooked . 

Animal Products 


. 95. 


• • 


40. 


82. 


• • 


97.6 


• • 




Meat meal (G) . . 


. . 


92. 


. . 


97. 


. . 


. . 


86. 




Dried blood (G) . 


. . 


72. 


. . 


72. 


. - 


92. 






Sour milk (G) . . 


. . 


95. 


. . 


96. 


. • 


98. 


95. 



3. FEEDING STANDARDS 



The feeding standards for the various classes of 
farm animals are taken from Mentzel & Lengerke's 
Landw. Kalender for 1899. They are intended to apply 
to animals of average size fed under normal conditions. 
They are not to be regarded as feeding recipes, but are 
to be varied according to circumstances. Small animals 
should receive proportionately more food than large 
ones ; milch cows in proportion to the quantity and 
richness of the milk ; growing and fattening animals 
according to the rapidity of increase desired ; work 



436 Appendix 

animals according to the severity of labor, and indi- 
vidual animals according to their peculiar needs. 

The quantity of "dry substance" will vary according 
to the digestibility of the ration, with no harm. It is 
important to maintain the necessary quantity of diges- 
tible dry substance. This should be somewhat more if 
the ration has a larger proportion of coarse materials 
than when it is mostly grain. The nutritive ratio may 
wisely vary according to the availability and price of 
feeding stuffs. The method of calculating a standard 
ration is explained in Chapter XIX. 

Per 1,000 Lbs. Live Weight, Daily 

Dry ^Digestible organic substances — • Nutri- 
sub- Pro- Carbo- tive 

Kind of animal stance tein hydrates Fat Total ratio 1: 

lbs. lbs. lbs. lbs lbs. 

1 . Oxen — 

At rest 18 .7 8. .1 8.8 11.8 

Ligktwork 22 1.4 10. .3 11.7 7.7 

Moderate work ... 25 2. 11.5 .5 14. 6.5 

Severe work .... 28 2.8 13. .8 16.6 5.3 

2 . Fattening bovines — 

First period .... 30 2.5 15. .5 18. 6.5 

Second period ... 30 3. 14.5 .7 18.2 5.4 

Third period . ... 26 2.7 15. .7 18.4 6.2 

3 . Milch cows — 

Daily milk yield 11 
lbs 25 1.6 10. .3 11.9 6.7 

Daily milk yield 16X 
lbs 27 2. 11. .4 13.4 6. 

Daily milk yield 22 

lbs 29 2.5 13. .5 16. 5.7 

Daily milk yield 27% 

lbs 32 3.3 13. .8 17.1 4.5 

4 . Sheep — 

Coarse wool .... 20 1.2 10.5 .2 11.9 9.1 

Fine wool 23 1.5 12. .3 13.8 8.5 



Feeding Standards 437 

Per 1,000 Lbs. Ltve Weight, Daily 

Dry ^—Digestible organic substances— - Nutri- 

sub- Pro- Carbo- tive 

Kind of animal stance tein hydrates Fat Total ratio 1: 

lbs. lbs. lbs. lbs. lbs. 

5 . Ewes, suckling lambs . 25 2.9 15. .5 18.4 5.6 

6 . Fattening sheep — 

First period .... 30 3. 15. .5 18.5 5.4 

Second period ... 28 3.5 14.5 .6 18.6 4.5 

7 . Horses — 

Light work 20 1.5 9.5 .4 11.4 7. 

Moderate work ... 24 2. 11. .6 13.6 6.2 

Severe work .... 26 2.5 13.3 .8 16.6 6. 

8 . Brood sows 22 2.5 15.5 .4 18.4 6.6 

9 . Fattening swine — 

First period .... 36 4.5 25. .7 30.2 5.9 

Second period ... 32 4. 24. .5 28.5 6.3 

Third period .... 25 2.7 18. .4 21.1 7. 

10 GROWING CATTLE 

Dairy Breeds 

Live weight 
Age in per head 

months lbs. 

2-3 150 . . 23 4. 13. 2. 21. 4.5 

3-6 300 . . 24 3. 12.8 1. 16.8 5.1 

6-12 500 . . 27 2. 12.5 .5 15. 6.8 

12-18 700 . . 26 1.8 12.5 .4 14.7 7.5 

18-24 900 . . 26 1.5 12. .3 13.8 8.5 

Beef Breeds 

2-3 165 . . 23 4.2 13. 2. 19.2 4.2 

3-6 330 . . 24 3.5 12.8 1.5 17.8 4.7 

6-12 550 . . 25 2.5 13.2 .7 16.4 6. 

12-18 750 . . 24 2. 12.5 .5 15. 6.8 

18-24 .... 935 . . 24 1.8 12. .4 14.2 7.2 

GROWING SHEEP 

Wool Breeds 

4-6 60 . . 25 3.4 15.4 .7 19.5 5. 

6-8 75 . . 25 2.8 13.8 .6 17.2 5.4 

8-11 85 . . 23 2.1 11.5 .5 14.1 6. 



438 Appendix 

Per 1,000 Lbs. Live Weight, Daily 
Dry /—Digestible organic substances— > Nutri- 

sub- Pro- Carbo- tive 

Kind of animal stance tein hydrates Fat Total ratio 1: 

lbs. lbs, lbs. lbs. lbs. 
Wool Breeds— continued 

Live weight 
Age in per head 

months lbs. 

11-15 90 . . 22 1.8 11.2 .4 13.4 7. 

15-20 100 . . 22 1.5 10.8 .3 12.6 7.7 

Mutton Breeds 

4-6 65 .26 4.4 15.5 .9 20.8 4. 

6-8 85 . . 26 3.5 15. .7 19.2 4.8 

8-11 100 . . 24 3. 14.3 .5 1.78 5.2 

11-15 120 . . 23 2.2 12.6 .5 15.3 6.3 

15-20 150 . . 22 2. 12. .4 12.4 6.5 

GROWING-SWINE 

Breeding Stock 

2-3 45 . . 44 7.6 28. 1. 35.7 4. 

3-5 100 . . 35 5. 23.1 .8 28.9 5. 

5-6 120 . . 32 3.7 21.3 .4 25.4 6. 

6-8 175 . 28 2.8 18.7 .3 21.8 7. 

8-12 260 . . 25 2.1 15.3 .2 17.6 7.5 

Growing Fattening Animals 

2-3 45 . . 44 7.6 28. 1. 35.7 4. 

3-5 110 . . 35 5. 23.1 .8 28.9 5. 

5-6 150 . . 33 4.3 22.3 .6 27.2 5.5 

6-8 200 . . 30 3.6 20.5 .4 24.5 6. 

8-12 275 . . 26 3. 18.3 .3 21.6 6.4 



Fertilizing Constituents 



439 



4. FERTILIZING CONSTITUENTS OF AMERICAN 
FEEDING STUFFS 

This table is the one prepared by the Office of Ex- 
periment Stations, U. 8. Department of Agriculture, 
and published in the Handbook of Experiment Sta- 
tion Work, Bulletin No. 15. 



Green Fodders 

Corn fodder 

Sorghum fodder 

Rye fodder 

Oat fodder 

Common millet 

Japanese millet 

Hungarian grass (German 
millet) 

Orchard grass (Dactylis 
glomerata)* 

Timothy grass (Phleum pra- 
tense)* 

Perennial rye grass (Lolium 
perenne)* 

Italian rye grass (Lolium 
italicum)* 

Mixed pasture grasses . . 

Red clover (Trifolium pra- 
tense) 

White clover (Trifolium re- 
pens) 

Alsike clover (Trifolium hy- 
bridum) 

Scarlet clover ( Trifolium in- 
carnatum) 

Alfalfa {Medicago sativa) . 



oisture 

% 


Ash 

% 


Nitrogen 
% 


Phos- 
phoric 
acid 

% 


Potas- 
sium 
oxide 

% 


78.61 


4.84 


.41 


.15 


.33 


82.19 


. 


.23 


.09 


.23 


62.11 


. 


.33 


.15 


.73 


83.36 


1.31 


.49 


.13 


.38 


62.58 


. . 


.61 


.19 


.41 


71.05 


• • 


.53 


.2 


.34 


74.31 


• • 


.39 


.16 


.55 


73.14 


2.09 


.43 


.16 


.76 


66.9 


2.15 


.48 


.26 


.76 


75.2 


2.6 


.47 


.28 


1.1 


74.85 


2.84 


.54 


.29 


1.14 


63,12 


3.27 


.91 


.23 


.75 


80. 


• • 


.53 


.13 


.46 


81. 


• • 


.56 


.2 


.24 


81.8 


1.47 


.44 


.11 


.2 


82.5 


m # 


.43 


.13 


.49 


75.3 


2.25 


.72 


.13 


.56 



♦Dietrich and Konig: Zusamensetzung und Verdaulichkeit der Futtermittei. 



440 



Appendix 



Moisture Ash 

% % 
Green Fodders— continued 

Cow pea 78.81 1.47 

Serradella (Ornithopis sa- 

tivus) 82.59 1.82 

Soja bean (Glycine soja) .73.2 

Horse bean (Vicia fdba) . . 74.71 . . 

White lupine (Lupinus albas) 85.35 . . 
Yellow lupine (Lupinus lu- 

teus)* 83.15 .96 

Plat pea (Lathyrus sylvestris)* 71. G 1.93 

Common vetch (Viciasativa)* 84.5 1.94 

Prickly comfrey (Symphy- 
tum asperrimum) .... 84.36 2.45 

Corn silage . . _. 77.95 . . 

Corn and soja bean silage . 71.03 . . 

Apple pomace silage* . . . 75. 1.05 

Hay and Dry Coarse Fodders 

Corn fodder (with ears) . . 7.85 4.91 

Corn stover (without ears) . 9.12 3.74 

TeosmteiEuchlamaluxurians) 6.06 6.53 

Common millet 9.75 . . 

Japanese millet 10.45 5.8 

Hungarian grass 7.69 6.18 

Hay of mixed grasses . . . 11.99 6.34 

Rowen of mixed grasses. . 18.52 9.57 

Redtop ( Agrostis vulgaris) . 7.71 4.59 

Timothy 7.52 4.93 

Orchard grass 8.84 6.42 

Kentucky blue -grass (Poa 

pratensis) 10.35 4.16 

Meadow fescue (Festuca pra- 
tensis) 8.89 8.08 

Tall meadow oat grass (Ar- 

rhenatcerum avenaceum) . 15.35 4.92 

* Dietrich and Konig. 



Phos- 
phoric 
Nitrogen acid 



.27 



1.19 

.99 

1.16 



.1 



.4 
.32 



Potas- 
sium 
oxide 



.31 



.41 


.14 


.42 


.29 


.15 


.53 


.68 


.33 


1.37 


.44 


.35 


1.73 


.51 


.11 


.15 


1.13 


.18 


.58 


.59 


1.19 


.7 


.42 


.11 


.75 


.28 


.11 


.37 


.79 


.42 


.44 


.32 


.15 


.4 


1.76 


.54 


.89 


1.04 


.29 


1.4 


1.46 


.55 


3.7 


1.28 


.49 


1.69 


1.11 


.4 


1.22 


1.2 


.35 


1.3 


1.41 


.27 


1.55 


1.61 


.43 


1.49 


1.15 


.36 


1.02 


1.26 


.53 


9 


1.31 


.41 


1.88 



1.57 

2.1 

1.72 



Fertilizing Constituents 



441 



Moisture Ash 

% % 

Hay and Dry Coarse Fodders— 
continued 

Meadow foxtail (Alopecurus 

pratensis) 15.35 5.24 

Perennial rye grass . ... 9.13 6.79 

Italian rye grass 8.71 

Salt marsh hay 5.3b" 

Japanese buckwheat ... 5.72 

Red clover 11.33 6.93 

Mammoth red clover (Tri- 

folium medium) 11.41 8.72 

White clover 

Scarlet clover* 18.3 7.7 

Alsike clover 9.94 11.11 

Alfalfa 6.55 7.07 

Blue melilot( Melilotus 

cceruleus) 8.22 13.65 

Bokhara clover (Melilotus 

alba) . . 7.43 7.7 

Sainfoin (Onobrychis sativa) 12.17 7.55 
Sulla (Jledysarum coro- 

narium) 9.39 . . 

Lotus villosus 11.52 8.23 

Soja bean (whole plant) . 6.3 6.47 

Soja bean (straw) .... 13. 

Cow pea (whole plant) . . 10.95 8.4 

Serradella . 7.39 10 6 

Scotch tares 15.8 . . 

Oxeye daisy ( Chrysanthe- 
mum leacanthemum) . . . 9.65 6.37 

Dry carrot tops 9.76 12.52 

Barley straw 11.44 5.3 

Barley chaff 13.08 . . 

Wheat straw 12.56 3.81 

Wheat chaff 8.05 7.18 

* Dietrich and Konig. 



itrogen 

% 


Phos- 
phoric 
acid 

% 


Potas- 
sium 
oxide 

% 


1.54 


.44 


1.99 


1.23 


.56 


1.55 


1.19 


.56 


1.27 


1.18 


.25 


.72 


1.63 


.85 


3.32 


2.07 


.38 


2.2 


2.23 


.55 


1.22 


2.75 


.52 


1.81 


2.05 


.4 


1.31 


2.34 


.67 


2.23 


2.19 


.51 


1.68 



1.92 



.54 2.8 



1.98 


.56 


1.83 


2.63 


.76 


2.02 


2.46 


.45 


2.09 


2.1 


.59 


1.81 


2.32 


.67 


1.08 


1.75 


.4 


1.32 


1.95 


.52 


1.47 


2.7 


.78 


.65 


2.96 


.82 


3. 


.28 


.44 


1.25 


3.13 


.61 


4.88 


1.31 


.3 


2.09 


1.01 


.27 


.99 


.59 


.12 


.51 


.79 


.7 


.42 



442 



Appendix 



Hay and Dry. Coarse Fodder s- 
continued 



Eye straw . . . 
Oat straw . . . 
Buckwheat hulls 



Moisture 

% 

7.61 
9.09 
11.9 



Boots, Btdbs, Tubers, etc. 

Potatoes 79.75 

Red beets 87.73 

Yellow fodder beets . . . 90.6 

Sugar beets 86.95 

Mangel -wurzels 87.29 

Turnips 89.49 

Rutabagas 89.13 

Carrots . . . ^ 89.79 

Grains and Other Seeds 

Corn kernels 10.88 

Sorghum seed 14. 

Barley* 14.3 

Oats 18.17 

Wheat (spring) 14.35 

Wheat ( winter) 14.75 

Rye 14.9 

Common millet 12.68 

Japanese millet 13.68 

Rice 12.6 

Buckwheat 14.1 

Soja beans 18.33 

Mill Products 

Corn meal 12.95 

Corn-and-cob meal .... 8.96 

Ground oats 11.17 

Ground barley 13.43 

Rye flour ........ 14.2 



Ash 

% 

3.25 

4.76 



.99 
1.13 

.95 
1.04 
1.22 
1.01 
1.06 
9.22 

1.53 

2.48 
2.98 
1.57 



.82 
4.99 

1.41 

3.37 

2.06 



Nitrogen 

% 

.46 
.62 
.49 

.21 
.24 
.19 
.22 
.19 
.18 
.19 
.15 

1.82 
1.48 
1.51 
2.06 
2.36 
2.36 
1.76 
2.04 
1.73 
1.08 
1.44 
5.3 

1.58 
1.41 
1.86 
1.55 

1.68 



Phos- 
phoric 
acid 



.28 

.2 

.07 

.07 

.09 

.09 

.1 

.09 

.1 

.12 

.09 

.7 
.81 
.79 
.82 
.7 
.89 
.82 
.85 
.69 
.18 
.44 
1.87 

.63 
.57 

.77 
.66 
.85 



Potas- 
sium 
oxide 



.79 
1.24 

.52 

.29 
.44 
.46 
.48 
.38 
.39 
.49 
.51 

.4 
.42 
.48 
.62 
.39 
.61 
.54 
.36 
.38 
.09 
.21 
1.99 

.4 
.47 
.59 
.34 

.65 



* Dietrich and KOnig. 



Fertilizing Constituents 



443 



Moisture Ash 

% % 
Mill Products — continued 

Wheat flour 9.83 1.22 

Pea meal 8.85 2.68 

By-products and Waste Materials 

Cora cobs 12.09 .82 

Hominy feed 8.93 2.21 

Gluten meal 8.59 .73 

Starch feed (glucose refuse) 8.1 . . 

Malt sprouts 10.38 12.48 

Brewers' grains (dry) . . . 6.98 6.15 

Brewers' grains (wet) . . 75.01 . . 

Rye bran 12.5 4.6 

Rye middlings* .... 12.54 3.52 

Wheat bran 11.74 6.25 

Wheat middlings 9.18 2.3 

Rice bran 10.2 12.94 

Rice polish 10.3 9. 

Buckwheat middlings* . . 14.7 1.4 

Cottonseed meal 9.9 6.82 

Cottonseed hulls 10.63 2.61 

Linseed meal (old process) 8.88 6.08 

Linseed meal (new process) 7.77 5.37 

Apple pomace 80.5 .27 

* Dietrich and Konig 



Nitrogen 

% 


Phos- 
phoric 
acid 

% 


Potas- 
sium 
oxide 

% 


2.21 


.57 


.54 


3.08 


.82 


.99 


.5 


.06 


.6 


1.63 


.98 


.49 


5.03 


.33 


.05 


2.62 


.29 


.15 


3.55 


1.43 


1.63 


3.05 


1.26 


1.55 


.89 


.31 


.05 


2.32 


2.28 


1.4 


1.84 


1.26 


.81 


2.67 


2.89 


1.61 


2.63 


.95 


.63 


.71 


.29 


.24 


1.97 


2.67 


.71 


1.38 


.68 


.34 


6.64 


2.68 


1.79 


.75 


.18 


1.08 


5.43 


1.66 


1.37 


5.78 


1.83 


1.39 


23 


.02 


.13 



INDEX 



Absorption of food, 119. 

Acids, 83; action on albuminoids, 65; 
action on carbohydrates, 86; fatty, 
90; influence on digestion, 139. 

Age, influence on production, 411. 

Air, carbon in, 13; hydrogen in, 15; 
nitrogen in, 16; oxygen in, 14. 

Albuminoids, 57; action of acids and 
alkalies on, 65; action of heat on, 64; 
action of ferments on, 63, 65; com- 
parative energy values of, 173; com- 
pounds among, 57; energy of, 162; 
modified, 62. 

Albumins, 58; in milk, meat, eggs, 58; 
in plants, 59; properties of, 58; where 
found, 58. 

Alfalfa, as soiling crop, 266; produc- 
tivity of, 261. 

Alkalies, action on albuminoids, 65. 

Amides, 69; value of, 179. 

Animal, globulins in, 60; water in, 38. 

Animal body, distribution of ash com- 
pounds in, 49. 

Animal heat, source of, 9. 

Animal life, relation of oxygen to, 14; 
relation of plant to, 7; relation to 
man, 1. 

Animal meal. 256. 

Animals, composition of bodies, 93 ; 
mineral compounds in, 48; problems 
in feeding. '■',-. proportions of elements 
in, 22; selection of, 411; treatment 
of, 416. 

Ash, compounds of, 41; compounds in 
different species, 44 ; distribution 
compounds of in plants, 45; in ani- 
mal, 49; elements of, 30; influence of 



manufacturing processes on, 47; in 
plants, 43; variations in species, 43. 
Assimilation, definitions of, 99. 

Beef, feeding for production of, 339. 

Beet sugar, residues from manufacture 
of, 240. 

Bile, 115; function of, 116. 

Blood, 142; corpuscles in, 143; mineral 
compounds of, 50. 

Bone, formation of, 152. 

Bovines, maintenance food for, 297; 
maintenance rations for, 299. 

Butter-milk, 254, 255; as food for swine, 
363. 

Breakfast foods, residues from, 232. 

Breed, influence on digestion, 138; in- 
fluence on production, 409, 411. 

Brewer's grains, 236; residues, 236. 

Butter, effect of foods on, 319. 

Calcium, sources of, 20; in nutrition, 20. 

Calf, growth of, 324; metabolism of, 
324. 

Calorie, definition of, 161. 

Calorimeter, 162; respiration form, 201. 

Calves, composition of, 403; feeding of, 
328; production with, 40-1, 405; skim- 
milk for, 329. 

Capillaries, blood, 119. 

Carbohydrates, 75; action of acids on, 
86: action of ferments, 86; animal, 84; 
characteristics of, 85; energy of, 162; 
elements in, 30; functions of, 155; in- 
fluence of excess of, 135; relative en- 
ergy values of, 172; variations in di- 
gestibility, 123. 



(445) 



446 



Index 



Carbon, 12; in crops, 13; supply of, 12, 
13. 

Carbonic acid, elimination of, 149. 

Casein, 66. 

Cattle foods, 203; chemical differences 
in, 248; classification of, 249; com- 
mercial, 227; production of, 258. 

Cellulose, 73 ; action of ferments on, 118 ; 
energy value of, 172. 

Chemical studies, knowledge from, 191. 

Chicks, food mixtures for, 396; rations 
for, 395. 

Chlorine, in nutrition, 19; sources of, 
19. 

Coarse foods vs. grains, 249. 

Colts, feeding of, 333; foods for, 337; 
mixtures for, 338; oats as food for, 
335. 

Combustion, measurement of, 200. 

Compounds, classes of, 28; elements in 
classes, 30. 

Cooking, influence on digestion, 132. 

Corn bran, 240. 

Cottonseed, 242; cake, 243; hulls, 243; 
meal, _'42; oil, 243. 

Cows, production with, 404, 405; selec- 
tion of, 409. 

Crops, carbon in, 13; forage, 204; legu- 
minous, 262; productive capacity. 260; 
soiling, 263; succession for soiling, 
265. 

Crude fiber, 72; digestibility of, 124. 

Curing, changes in, 205; conditions of, 
206; vs. ensiling, 217. 

Dairy by-products, 254. 

Dextrose, 82. 

Diastase, function of, 87, 

Digestibility, determination of, 139; in- 
fluence of combination of nutrients 
on, 135; conditions influencing, 126. 

Digestion, energy required for, 165; of 
food, 98. 

Dried blood. 256. 

Ducks, food mixtures for, 396; rations 
for, 395. 



Elements, chemical, of nutrition, 11; 
proportions in animals, 22; propor- 
tions in plants, 21; sources of, 12. 

Energy, available, 163; carbohydrates 
as source of, 155; expended by work 
horses, 369; fats as source of, 157; 
food as source of, 157; in various food 
compounds, 162; manifestations of, 
159; measurement of available, 174; 
net, 164 ; of albuminoids, 173 ; of 
carbohydrates, 172; of cellulose, 172; 
of digested nutrients, 199; of fats, 
173; of gums, 173; of ration, calcula- 
tion of, 198 ; protein as source of, 
155; required for chewing, 165; source 
of, 8; unit of, 161; uses of , 157. 

Ensilage, 212; crops for, 218. 

Ensiling vs. field curing, 217. 

Enzyms, 103. 

Ether extract, 89; composition of, 92, 
digestibility of, 124. 

Ewes, feediug of, 331. 

Exercise, need of, 415. 

Extractives, 70; value of, 179. 

Fat, of milk, 91; study of formation, 
195. 

Fats, 88; absorption of, 120; compara- 
tive energy values of, 173 ; digesti- 
bility of, 124; elements in, 30; energy 
of, 162; functions of, 157; influence 
on digestion, 137 ; neutral, 90 ; of 
body, source of, 154, 156; production 
value of, 176. 

Fattening, feeding for, 341, 351. 

Feces, 121. 

Feeding, frequency of, 134. 

Feeding animals, problems in, 3. 

Feeding standards, 282. 

Feeding experiments, utility of, 188. 

Feeding stuffs, classification of, 251; 
commercial, 227; commercial values 
of, 269; composition of, 419; digesti- 
ble substance in, 276; digestibility of, 
427; energy of, 163; fertilizing con- 
stituents of, 439 ; physiological values 



Index 



447 



of, 272; popular valuation, 277; rela- 
tion to digestive processes, 121 ; selec- 
tion of, 273; valuation by cow, 279; 
valuation by experiments, 278; valua- 
tions of, 268; variations, water in, 37; 
water in, 36; water in air dry, 37; 
water in green, 36. 

Feeds, ash in, 47. 

Fermentations, in alimentary canal, 118. 

Ferments, 99; action on carbohydrates, 
86; coagulating, 63; of digestion, 65; 
organized, 100; unorganized, 100,103. 

Fibrinogen, 61. 

Fish offals, 256. 

Fodders, dried, 205; green, 205. 

Food, absorption of, 119; digestion of, 
98; distribution of, 142; influences on 
flavor of milk, 321 ; relation to growth, 
324; relation to milk, 316; relation to 
production, 194, 400; units of value, 
401; use of, 142, 147. 

Foods, of animal origin, 252. 

Forage crops, 204; for fattening sheep, 
357; influence of stage of growth on 
composition, 209; influence of stage of 
growth on yield, 208; harvesting of, 
207. 

Fowls, composition of bodies of, 387, 
403; digestive apparatus of, 383; feed- 
ing of, 379; production with, 404, 405. 

Fruit sugar, 83. 

Gases, of digestion, 164. 

Gastric juice, 112. 

Gelatinoids, 68. 

Germ oil meal, 240. 

Globulins, 59; in animal, 60; in seeds, 

59; properties of, 59. 
Glucose manufacture, residues from, 

236. 
Gluten, energy of, 175; productive value 

of, 177. 
Gluten feed, 239. 
Gluten meal, 239. 
Glycogen, 84; formation of, 150. 
Grains (and seeds), 225. 



Grape sugar, 82. 

Grasses, 204. 

Grinding grains, influence on digestion, 

133. 
Growing animals, feeding of, 324. 
Growth, relation to food, 325; sustained 

by plant, 8. 
Gums, energy value of, 173; digestibility 

of, 124; vegetable, 78. 

Hay, water in, 37. 

Heart, the, 144. 

Heat, body, regulation of, 168 ; effect 
on albuminoids, 64; effect on carbo- 
hydrates, 86. 

Hens, laying, rations for, 393. 

Hogs, fattening, growth of, 358. 

Horses, influence of speed on work of, 
370; maintenance food for, 300; main- 
tenance rations for, 302 : work per- 
formed by, 368; working, feeding of, 
367; working, foods for, 376; work- 
ing, food needs of, 371 ; working, 
rations for, 377 ; working, source of 
rations, 374. 

Hydrochloric acid, in stomach, 112. 

Hydi-ogen, 15; in air, 15; in water, 15; 
source to animal, 16. 

Intestinal juice, function of, 118. 
Intestines, the, 114. 
Investigation, methods of, 192. 
Iron, compounds of, 20; in nutrition, 20. 

Keratin, 69. 

Knowledge, sources of, 186. 

Lact-albumin, 59. 

Lacteals, 119. 

Lambs, fattening, experiments with, 

353 ; feeding of, 331. 
Laws of nutrition, 182. 
Legumes, 204. 
Levulose, 83. 
Lime, in animal, 48 ; for poultry, 390 ; 

in plants, 45. 



448 



Index 



Linseed meal, 245 ; new process, 246 ; 

old process, 246. 
LinseeJ oil. 245. 
Liver, the, 150. 
Lungs, the, 146. 

Maintenance food for bovines, 297; for 

horses, 300. 
Maintenance rations, 295; for bovines, 

299; for horses, 302; for poultry, 393; 

sources of, 296; uses of, 295. 
Maize, influence stage of growth, 211; 

productivity of, 261. 
Maize kernel, 237. 
Malt sprouts, 236. 
Maltose, 82. 

Man, relation to animal, 1. 
Mares, feeding of, 334. 
Matter, classes of, 26 ; combustible, 

26; incombustible, 26; inorganic, 28; 

organic, 28. 
Meat, albumin in, 58 ; production of, 

339. 
Meat meal, 256. 
Metabolic wastes, errors caused by, 136, 

140. 
Milk, composi.ionof, 305; as cattle food, 

252; demands for secretion of, 309; 

effect of food on, 313, 321; formation 

solids, 308; of various species, 253; 

production of, 304; protein needs for 

production of, 310; ration for produc- 
ing, 309, 312; secretion of, 306; source 

of solids, 307 ; sources protein in ration 

for, 313. 
Milk sugar, 85. 
Mineral compounds, elimination of, 149 ; 

function of, 152. 
Molasses, energy of, 175 ; production 

value of, 177. 
Mouth, the, 104. 
Mutton, production of, 349. 
Muscular power, source in plants, 9. 
Muscular tissue, 153. 
Mastication, energy requirements, 

1C5. 



Nitrogen, 16; compounds, 16, 51; in air, 
16; in soil, 16. 

Nitrogen-free compounds, 71. 

Nitrogen-free extract, 74; energy values 
of compounds, 171. 

Nuclein, 67: special value of, 180. 

Nutrients, combustion of, 147; energy 
relations of, 166; functions of, 151; 
physiological values of, 170; produc- 
tion values of, 175; relative energy 
values of, 171 ; storage of, 147. 

Nutrition, chemical elements of, 11; 
compounds of, 25; laws of , 182. 

Nutritive ratio, 283. 

■» 

Oat feeds, 233; grain, 233; hulls, 233; 
kernel, 233. 

Oats, as food for colts, 335. 

Oils, energy of, 175; productive value 
of, 177. 

Oil meals, 241. 

Oils, the, 88. 

Ova- albumen, 59. 

Oxygen, 14; in air, 14; in earth, 14: in 
lungs, 146; in water, 14; relation to 
animal life, 14; relation to energy, 15; 
use of, 147. 

Oxen, fattening, experiments with, 
343. 

Palatableness, importance of, 2S0; in- 
fluence on digestion, 126. 

Pancreatic juice, 117; function of, 117. 

Pectin bodies, 80. 

Pentosans, energy value of, 173. 

Pepsin, 113. 

Peptones, absorption of, 120. 

Phosphoric acid, in animal, 48; varia- 
tions in plants, 45. 

Phosphorus, in nutrition, 19; sources 
of, 18. 

Physiological studies, knowledge from, 
191. 

Pig, fat, composition of, 359; feeding 
of, 361; foods for, 3G3, 365; relation 
of food to growth, 362. 



Index 



449 



Plants, relation to animal life, 7, 8, 9; 
albumin in, 59; distribution ash com- 
pounds in, 45; living, water in, 33; 
mineral compounds of, 43 ; propor- 
tions of elements in, 21. 

Potash, variations in plants, 45. 

Pork, production of, 357. 

Potassium, where found, 19; in nutri- 
tion, 19. 

Poultry, effects of food with, 382; feed- 
ing of, 379; foods for, 379; food needs 
of, 389; food mixtures for, 396; main- 
tenance rations for, 393; rations for 
chicks, 394; rations for laying hens, 
393. 

Practice, conclusions of, 187. 

Preservation of fodders, influence on 
digestion, 129. 

Preparation of foods, influence on diges- 
tion, 129. 

Production, relation of food to, 194, 400; 
unit of, 401. 

Proteids, 55; composition, 56 ; com- 
pound, 66; examples of, 57. 

Protein, classification compounds of, 
54; combustion of, 147; definition of, 
52; elements in, 30; functions of, 153; 
how estimated, 53; in fattening ra- 
tion, 341, 352; in work horse ration, 
375; influence on digestion, 137; need 
of in milk ration, 310 ; production 
value of, 175; proportion in ration, 
291; relation to muscular effort, 167; 
relative importance of compound, 178; 
supply of, 262; sources of for milk 
ration, 313; variations in digestibility 
of, 122. 

Ptyalin, 107. 

Ration, influence of quantity on digest- 
ibility, 127. 

Rations, adaptation of, 281; calculation 
of, 285; compounding of, 280; fat- 
tening, selection of, 347; for fatten- 
ing steers. 342. 348; for laying hens, 
393; for milk production, 309, 312; 

cc 



for poultry, 392; for work horses, 
374, 377; for young birds, 394; main- 
tenance, 295; maintenance for bo- 
vines, 299; maintenance for horses, 
302; maintenance for poultry, 393; 
manipulation of, 413; palatableness 
of, 280; proportion of protein, 291; 
quantity of, 414; relation to quality 
of product, 292; relation to prices and 
supply, 293 ; relation to weight of 
animal, 289; selection of, 280; stand- 
ards for, 282, 342, 345. 

Rennin, 113. 

Respiration apparatus, 196. 

Rigor mortis, cause of, 61. 

Roots (and tubers), 224. 

Roots, productivity of, 261; storage of, 



Saccharose, 81. 

Saliva, 106; function of, 107. 

Salt, in feeding poultry, 391; influence 
on digestion, 133. 

Salts, absorption of, 120. 

Sand, in feeding poultry, 391. 

Serum albumin, 59. 

Sheep, composition of, 403; fattening, 
experiments with, 353 ; fattening, food 
needs of, 351; fattening, food stand- 
ards, 352; fattening, growth of, 350; 
production with, 404, 405 ; selection 
of ration for, 355. 

Silage, 212; changes in, 213 ; cutting 
material for, 221; formation of, 213; 
maturity crop for, 220. 

Silo, construction of, 219; changes in, 
213; extent of loss from, 215; filling 
of, 220; nature of loss from, 214; rate 
of filling, 221. 

Skim-milk, 254, 255; as food for swine, 
363. 

Slaughter-house refuses, 256. 

Sodium, in nutrition, 20; sources of, 19. 

Soil, nitrogen in, 16. 

Soiling, 263; crops for, 265; succession 
of crops, 266; systems of, 265. 



450 



Index 



Soiling crops, for swine, 366. 

Sows, feeding of, 360. 

Species, influence on digestion, 137. 

Stage of growth, influence on digestion, 
130 ; influence on forage crops, 208. 

Standards, German, 282. 

Starch, energy of, 175; distribution in 
seeds, 77 ; productive value of, 176, 
177; properties of, 76; residues from 
manufacture of, 236. 

Starch (sugar corn) feed, 239. 

Stai'ch grains, forms of, 76. 

Starches, the, 75. 

Steers, composition of, 403 ; composi 
tion of increase of, 340 ; fattening 
experiments with, 343, 345; fattening 
food needs of, 341; fattening, food for 
344; production with, 404, 405. 

Stomach, 108; of horse, 113; of pig, 113 
of ruminants, 1087 

Storage, influence on digestibility, 135. 

Straw, energy of, 175; production value 
of, 177. 

Straws, the, 223. 

Sugar, absorption of, 120. 

Sugar beet molasses, 241. 

Sugar beet pulp, 240. 

Sugars, the, 80. 

Sulfur, in nutrition, 18; sources of, 18. 



Swine, composition of , 403« production, 
404, 405. 

Teeth, the, 105. 
Temperature of stable, 415. 
Trypsin, 117. 

Urea, elimination of , 149. 

Valuation feeding stuffs, 268; basis of, 
274 ; commercially, 269 ; physiologi- 
cally, 272; popular standards, 277. 

Vitellin, 62. 

Water, 30; amount required by plants, 
36; elimination of , 149; hydrogen in, 
15 ; in animal, 38 ; in fattening in- 
crease, 40; in feeding poultry, 389; in 
feeding stuffs, 36; in hay, 37; in liv- 
ing plants, 33; oxygen in, 14; varia- 
tions in feeding stuffs, 37; in plants, 
33. 

Watering, frequency of, 134. 

Wastes, elimination of, 148. 

Wheat, offals from, 228. 

Wheat kernel, 228 ; proportion of parts, 
230. 

Wheat offals, composition of, 231. 

Whey, 254, 255. 



The Best and Newest 
Rural Books 



BOOKS ON LEADING TOPICS 
CONNECTED WITH AGRI- 
CULTURAL AND RURAL 
LIFE ARE HERE MENTIONED. 
EACH BOOK IS THE WORK 
OF A SPECIALIST, UNDER THE 
EDITORIAL SUPERVISION OF 
PROFESSOR L. H. BAILEY, OF 
THE CORNELL UNIVERSITY, 
OR BY PROFESSOR BAILEY 
HIMSELF, AND IS READABLE, 
CLEAR-CUT AND PRACTICAL. 



THE RURAL SCIENCE SERIES 

Includes books which state the underlying principles 
of agriculture in plain language. They are suitable 
for consultation alike by the amateur or professional 
tiller of the soil, the scientist or the student, and are 
freely illustrated and finely made. 

The following volumes are now ready: 

THE SOIL. By F. H. King, of the L T niversity of Wisconsin. 303 pp. 45 
illustrations. 75 cents. 

THE FERTILITY OF THE LAND. By I. P. Roberts, of Cornell Univer- 
sity. 421 pp. 45 illustrations. $1.25. 

THE SPRAYING OF PLANTS. By E. G. Lodeman, late of Cornell Uni- 
versity. 399 pp. 92 illustrations. $1.00. 

MILK AND ITS PRODUCTS. By H. H. Wing, of Cornell University. 
311 pp. 43 illustrations. $1.00. 

THE PRINCIPLES OF FRUIT-GROWING. By L. H. Bailey. 516 pp. 
120 illustrations. $1.25. 

BUSH-FRUITS. By F. W. Card, of Rhode Island College of Agriculture 
and Mechanic Arts. 537 pp. 113 illustrations. $1.50. 

FERTILIZERS. By E. B. Voorhees, of New Jersey Experiment Station. 
332 pp. $1.00. 

THE PRINCIPLES OF AGRICULTURE. By L. H. Bailev. 300 pp. 92 
illustrations. $1.25. 

IRRIGATION AND DRAINAGE. By F. H. King, University of Wisconsin. 
502 pp. 163 illustrations. $1.50. 

THE FARMSTEAD. By I. P. Roberts. 350 pp. 138 illustrations. $1.25. 

RURAL WEALTH AND WELFARE. By George T. Fairchild, Ex-Presi- 
dent of the Agricultural College of Kansas. 381 pp. 14 charts. $1.25. 

THE PRINCIPLES OF VEGETABLE-GARDENING. By L. H. Bailey. 
468 pp. 144 illustrations. $1.25. 

THE FEEDING OF ANIMALS. By W. H. Jordan, of New York State 
Experiment Station. 450 pp. $1.25 net. 

FARM POULTRY. By George C. Watson, of Pennsylvania State College. 
341 pp. $1.25 net. 

THE FARMER'S BUSINESS HANDBOOK. By I. P. Roberts, of Cornell 
University. 300 pp. $1.00 net. 

New volumes will be added from time to time to 
the Rural Science Series. The following are in 
preparation : 

PHYSIOLOGY OF PLANTS. By J. C. Arthur, Purdue University. 

THE PRINCIPLES OF STOCK BREEDING. By W. H. Brewer, of Yale 
University. 

PLANT PATHOLOGY. By B. T. Galloway and associates, of U. S. Depart- 
ment of Agriculture. 

CARE OF ANIMALS. By N. S. Mayo, of Connecticut Agricultural College. 

THE POME FRUITS (Apples, Pears, Quinces). By L. H. Bailey. 



THE GARDEN-CRAFT SERIES 

Comprises practical handbooks for the horticultur- 
ist, explaining and illustrating in detail the various 
important methods which experience has demon- 
strated to be the most satisfactory. They may be 
called manuals of practice, and though all are pre- 
pared by Professor Bailey, of Cornell University, 
they include the opinions and methods of success- 
ful specialists in many lines, thus combining the 
results of the observations and experiences of nu- 
merous students in this and other lands. They are 
written in the clear, strong, concise English and in 
the entertaining style which characterize the author. 
The volumes are compact, uniform in style, clearly 
printed, and illustrated as the subject demands. 
They are of convenient shape for the pocket, and 
are substantially bound in flexible green cloth. 

THE HORTICULTURIST'S RULE BOOK. By L. H. Bailey. 312 pp. 
75 cents. 

THE NURSERY-BOOK. By L. H. Bailey. 365 pp. 152 illustrations. $1. 

PLANT-BREEDING. By L. H. Bailey. 293 pp. 20 illustrations. $1.00. 

THE FORCING-BOOK. By L. H. Bailey. 266 pp. 88 illustrations. $1.00. 

GARDEN-MAKING. By L. H. Bailey. 417 pp. 256 illustrations. $1.00. 

THE PRUNING-BOOK. By L. H. Bailey. 545 pp. 331 illustrations. $1.50. 

THE PRACTICAL GARDEN-BOOK. By C. E. HuKN and L. H. Bailky. 

250 pp. Many marginal cats. $1.00. 



T 



WORKS BY PROFESSOR BAILEY 

HE SURVIVAL OF THE UNLIKE: 

A Collection of Evolution Essays Suggested 
by the Study of Domestic Plants. By L. H. 

BAILEY, Professor of Horticulture in the Cornell 
University. 

FOURTH EDITION — 51 S PACES — 22 ILLUSTRATIONS — $2. 00 

To those interested in the underlying philosophy 
of plant life, this volume, written in a most enter- 
taining style, and fully illustrated, will prove wel- 
come. It treats of the modification of plants under 
cultivation upon the evolution theory, and its atti- 
tude on this interesting subject is characterized 
by the author's well-known originality and inde- 
pendence of thought. Incidentally, there is stated 
much that will be valuable and suggestive to the 
working horticulturist, as well as to the man or 
woman impelled by a love of nature to horticul- 
tural pursuits. It may well be called, indeed, a 
philosophy of horticulture, in which all interested 
may find inspiration and instruction. 

The Survival of the Unlike comprises thirty essays touching 
upon The General Fact and Philosophy of Evolution (The Plant 
Individual, Experimental Evolution, Coxey's Army and the Russian 
Thistle, Recent Progress, etc.); Expounding the Fact and Causes of 
Variation (The Supposed Correlations of Quality in Fruits, Natural 
History of Synonyms, Reflective Impressions, Relation of Seed- 
bearing to Cultivation, Variation after Birth, Relation between 
American and Eastern Asian Fruits, Horticultural Geography, Prob- 
lems of Climate and Plants, American Fruits, Acclimatization, Sex 
in Fruits, Novelties, Promising Varieties, etc.); and Tracing the 
Evolution of Particular Types of Plants (the Cultivated Strawberry, 
Battle of the Plums, Grapes, Progress of the Carnation. Petunia. 
The Garden Tomato, etc.). 



T 



WORKS BY PROFESSOR BAILEY 

HE EVOLUTION OF OUR NA- 
TIVE FRUITS. By L. H. BAILEY, Pro* 
fessor of Horticulture in the Cornell University. 

478 PACES -126 ILLUSTRATIONS — 82. 00 

In this entertaining volume, the origin and de- 
velopment of the fruits peculiar to North America 
are inquired into, and the personality of those horti- 
cultural pioneers whose almost forgotten labors 
have given us our most valuable fruits is touched 
upon. There has been careful research into the 
history of the various fruits, including inspection 
of the records of the great European "botanists who 
have given attention to American economic botany. 
The conclusions reached, the information presented, 
and the suggestions as to future developments, can- 
not but be valuable to any thoughtful fruit-grower, 
while the terse style of the author is at its best in 
hi? treatment of the subject. 

The Evolution of our Native Fruits discusses The Rise of 
the American Grape (North America a Natural Vineland, Attempts 
to Cultivate the European Grape, The Experiments of the Dufours, 
The Branch of Promise, John Adlum and the Catawba, Rise of 
Commercial Viticulture, Why Did the Early Vine Experiments Fail < 
Synopsis of the American Grapes) ; The Strange History of the Mul 
berries (The Early Silk Industry, The "Multicaulis Craze,") ; Evolu- 
tion of American Plums and Cherries (Native Plums in Genera!, 
The Chickasaw, Hortulana, Marianna and Beach Plum Groups, 
Pacific Coast Plum, Various Other Types of Plums, Native Cherries, 
Dwarf Cherry Group ) ; Native Apples (Indigenous Species, Amelio- 
ration has begun); Origin of American Raspberry-growing (Early 
American History, Present Types, Outlying Types) ; Evolution of 
Blackberry and Dewberry Culture (Tbe High-bush Blackberry and 
Its Kin, The Dewberries, Botanical Names); Various Types of 
Berry-like Fruits (The Gooseberry, Native Currants, Juneberry, 
Buffalo Berry, Elderberry, High-bush Cranberry, Cranberry, Straw- 
berrv); Various Types of Tree Fruits (Persimmon, Custard-Applo 
Tribe, Thorn-Apples, Nut-Fruits) ; General Remarks on the Improve- 
ment of our Native Fruits (What Has Been Done, What Probably 
Should Be Done). 



L 



WORKS BY PROFESSOR BAILEY 

ESSONS WITH PLANTS: Sugges- 
tions for Seeing and Interpreting Some of 
the Common Forms of Vegetation. By L. 

H. BAILEY, Professor of Horticulture in the Cornell 
University, with delineations from nature by W. S. 
HOLDSWORTH, of the Agricultural College of 
Michigan. 

SECOND EDITION— 491 PACES— 446 ILLUSTRATIONS— 1 2 MO- 
CLOTH— SI. 10 NET 

There are two ways of looking at nature. The 
old way, which you have found so unsatisfactory, 
was to classify everything — to consider leaves, roots, 
and whole plants as formal herbarium specimens, 
forgetting that each had its own story of growth 
and development, struggle and success, to tell. 
Nothing stifles a natural love for plants more effect- 
ually than that old way. 

- The new way is to watch the life of every grow- 
ing thing, to look upon each plant as a living 
creature, whose life is a story as fascinating as the 
story of any favorite hero. "Lessons with Plants" 
is a book of stories, or rather, a book of plays, for 
we can see each chapter acted out if we take the 
trouble to look at the actors. 

" I have spent some time in most delightful examination of it, and the 
longer I look, the better I like it. I find it not only full of interest, but 
eminently suggestive. I know of no book which begins to do so much to 
open the eyes of the student —whether pupil or teacher — to the wealth of 
meaning contained in simple plant forms. Above all else, it seems to be 
full of suggestions that help one to learn the language of plants, so they 
may talk to him."— Darwin L. Bardwell, Superintendent of Schools, Bing- 
hamton. 

"It is an admirable book, and cannot fail both to awaken interest in 
the subject, and to serve as a helpful and reliable guide to young students 
of plant life. It will, I think, fill an important place in secondary schools, 
and comes at an opportune time, when helps of this kind are needed and 
eagerly sought."— Professor V. M. Spalding, University of Michigan. 

FIRST LESSONS WITH PLANTS 

An Abridgement of the above. 117 pages — 116 illustra- 
tions — 40 cents net. 



WORKS BY PROFESSOR 3AILEY 



B 



OTANY : An Elementary Text for Schools. 

By L. H. BAILEY. 

355 PACES— 500 ILLUSTRATIONS— $1 .10 NET 



"This book is made for the pupil: 'Lessons With Plants' 
was made to supplement the work of the teacher." This is the 
opening sentence of the preface, showing that the book is a 
companion to "Lessons With Plants," which has now become a 
standard teacher's book. The present book is the handsomest 
elementary botanical text-book yet made. The illustrations 
illustrate. They are artistic. The old formal and unnatural 
Botany is being rapidly outgrown. The book disparages mere 
laboratory work of the old kind: the pupil is taught to see things 
as they grow and behave. The pupil who goes through this book 
will understand the meaning of the plants which he sees day 
by day. It is a revolt from the dry -as -dust teaching of botany. 
It cares little for science for science' sake, but its point of view 
is nature -study in its best sense. The book is divided into four 
parts, any or all of which may be used in the school: the plant 
itself; the plant in its environment; histology, or the minute 
structure of plants; the kinds of plants (with a key, and de- 
scriptions of 300 common species). The introduction contains 
advico to teachers. The book is brand new from start to 
finish. 

"An exceedingly attractive text-book."— Educational Review. 
"It is a school book of the modern methods."— The Dial. 

"It would be hard to find a better manual for schools or for indi- 
ridual use." — The Outlook. 



THE MACMILLAN COMPANY 

No. 66 Fifth Avenue NEW YORK 



T 



WORKS BY PROFESSOR BAILEY 

HE CYCLOPEDIA OF AMERICAN 
HORTICULTURE : By l. h. bailey, of 

Cornell University, assisted by WILHELM MILLER, 
and many expert cultivators and botanists. 

4 VOLS.— OVER 2800 ORIGINAL ENGRAVINGS -CLOTH — OCTAVO 
$20.00 NET PER SET. HALF MOROCCO, $32.00 NET PER SET 

This great work comprises directions for the cul- 
tivation of horticultural crops and original descrip- 
tions of all the species of fruits, vegetables, flowers 
and ornamental plants known to be in the market in 
the United States and Canada. "It has the unique 
distinction of presenting for the first time, in a care- 
fully arranged and perfectly accessible form, the best 
knowledge of the best specialists in America upon 
gardening, fruit-growing, vegetable culture, forestry, 
and the like, as well as exact botanical information. 
. . . The contributors are eminent cultivators or 
specialists, and the arrangement is very systematic, 
clear and convenient for ready reference." 

''We have here a work which every ambitious gardener -will wisli to place 
on his shelf beside his Nicholson and his Loudon, and for such users of it a 
too advanced nomenclature would have been confusing to the last degree. 
With the safe names here given, there is little liability to serious perplexity. 
There is a growing impatience with much of the controversy concerning 
revision of names of organisms, whether of plants or animals. Those in- 
vestigators who are busied with the ecological aspects of organisms, and 
also those who are chiefly concerned with the application of plants to the 
arts of agriculture, horticulture, and so on, care for the names of organisms 
under examination only so far as these aid in recognition and identification. 
To introduce unnecessary confusion is a serious blunder. Professor Bailey 
has avoided the risk of confusion. In short, in range, treatment and edit- 
ing, the Cyclopedia appears to be emphatically useful ; . . . a work worthy 
of ranking by the side of the Century Dictionary." — The Nation. 

This work is sold only by subscription, and terms and 
further information may be had of the publishers. 

THE MACMILLAN COMPANY 

No. 66 Fifth Avenue NEW YORK 



APR 1 11904 



